10/24/2014: 10 Leader Guides are undone, but the rest of the guide is 95%+ complete. I will work on this eventually but have my hands full playing Civilization: Beyond Earth and writing for The Sims 4. There is a possibiliy I will try to cover at least some of the gameplay elements from Beyond Earth, but can't make any promises. If you'd like to say thanks, you can use the donate button or use EA Origin, Gamestop, or Walmart to make a game purchase.
Civilization 5 Brave New World
Theming Bonus Requirements List & Strategy Guide
Theming Bonuses allow you to milk a bit more Culture and Tourism out of your Civ's Great Works of Art, Music, Writing, and Artifacts found by Archaeologists. This Guide will teach you how to use this feature to aid in Cultural Victory, or simply boost your Culture per turn a few notches to Adopt new Social Policies faster or help fend off another Civ's Culture to prevent their Victory. Knowledge of each building's requirements can help you to plan and maximize Tourism output for a faster victory.
How it Works
Click on Culture Overview in the top-right portion of the screen to access the Great Works management area and also see how your Tourism stacks up against other Civs'. Using the interface is simple, just click on a Work and the slot you'll move/swap it to. Hovering over a building that indicates +0 will show what you're supposed to do in-game, while I've provided a full list of buildings that offer bonuses below to help you seek Wonders and Technologies that will let you take advantage of this feature.
Swapping Great Works
You can aid yourself in the acquisition of Great Works of Writing, Art, and Artifacts (but not Music) by swapping those you don't need with the AI through the top of this same Culture Overview screen. These three types may only be traded for the same kind, but you can see what other Players and the AI are offering to get rid of out of their collections. The +X next to each Great Work or Artifact shows you whether it's currently receiving a Theming Bonus. Put those you know you won't need up for trade with other Civs. Every Civ would do well to trade a couple Works of Writing to slip into their Oxford University, as they must come from other Civs.
Museums get special mention here, as they'll aid a bit in boosting your Theming on a Civ-wide scale. Museums only give +1 Theming bonuses but can be built by any City that has also built a Monument, Amphitheater, and an Opera House. They are special in this regard, for every other type of building that isn't a World Wonder or National Wonder does not offer a theming bonus at all, so it's worth swapping these around and ensuring that you pick up that second Artifact and knowing which kind to choose.
Art and Artifacts
You can fit Artifacts into any building's Art slot, but that is only for storage. Artifacts do not count as Art for theming bonuses and are only used by the Louvre and Museums. Great Works of Art are created by Great Artists, while Artifacts are found by Archaeologists. When an Archaeologist digs up an Antiquity Site or Hidden Antiquity Site, you'll get an option to build a Landmark or take an Artifact. Sometimes you will get to choose among a couple types of Artifacts. It's worth noting that Barbarians and each individual City State count as Civilizations when it comes to the Museum and Louvre Theming bonuses. Unfortunately, taking all the Exploration Social Policies to reveal these Hidden Antiquity sites is hardly worth it unless you're on a map with loads of water and need those boosts already. Rival Civs will see that you've dug something up within their territory, so it doesn't help with that, nor are there any special artifacts to be found within - they're just less likely to be excavated by other Civs before you get there.
|Building||Technology||Bonus*||Great Work/Artifact Requirements||Collection Name|
|The Great Library|
|Writing||+2||Two Works of Writing of different Eras from two Civs||Library of Ancient Knowledge|
University in All Cities
|+2||Two Works of Writing of two other Civs of two different Eras||Library of World Literature|
|Printing Press||+2||Two Works of Writing by one Civ, both from the same Era||Theater of (Era) (Civ) Literature|
|Acoustics||+2||Two Works of Art by one Civ from the same Era||Chapel of (Era) (Civ) Art|
& Opera in All Cities
|+3||Three Works of Art by Three different Civs||Museum of World Art|
|Architecture & Adopt Aesthetics>||+3||Three Works of Art by one Civ from the same Era||Museum of (Era) (Civ) Art|
|Sydney Opera House|
|Ecology||+2||Two Works of Music from different Eras by the same Civ||Center for the (Civ) Musical Arts|
|Radio||+3||Three Works of Music from the same Era from the same Civ||Showplace for (Era) (Civ) Music|
|Archaeology||+1/+2||Either two Works of Art or two Artifacts from your Civ or two Civs other than yours (can be two different foreign Civs) for +1. If it is fulfilling both requirements (same type and from the same Era) and either your Civ or from Civs other than yours, you get +2.|
& Adopt Exploration
|+4||Two Artifacts and two Works of Art, all from different Eras and Civilizations||World's Most Visited Museum|
*Double Theming: Aesthetics Social Policies and France
Taking all the Aesthetics Social Policies will allow you to get double for all Theming Bonuses in the above list. France gets double that again for their City of Light special, but only for Theming Bonuses in Paris, which makes them highly suitable for a Cultural Victory that focuses on ensuring you get at least some of these Wonders in your Capital. France gets an achievement for taking all of Aesthetics and getting the maximum bonus for the Louvre, at +16 (4x2x2).
Getting The Great Works and Wonders through War
If you lack Great Works from earlier Eras or from other Civs, you may resort to War in order to get it. When you conquer a City, you'll capture any Great Works that were stored there, although your enemies can certainly move them to avoid you capturing them - it all depends on the slots they have available and whether they bother to do so. You certainly should move Works and Artifacts out of any City that is about to be conquered if you're on the receiving end of this strategy. It is particularly helpful even in such a peaceful victory type as Culture, for you are at once stifling an opponent's Cultural Output while simultaneously raising your Tourism Output. Use the Culture Overview to help you see which opponents are going to take the longest to overtake, as they likely have Cultural Wonders and Works that you can take for yourself should you be capable of doing so without landing yourself in a massive war or angering an ally.
Maximizing Tourism and Theming
Theming Bonuses are taken into account along with the +Tourism from your Great Works and Artifacts before any percentages kick in, so you can expect to get much more than +8 out of the Louvre depending on all the factors that increase Tourism, which are outlined in the Cultural Victory Guide.
I think you can tell what ones already are involved in Theming Bonuses as they have +0 or +1/2 next to them, so that you don't have to worry about trading something you are already using in theming.
I myself found the Louvre to be really complicated at first, but so long as you're active with Archaeologists it is easy to get 2 artifacts from Civs that are not your own (city-states/barbarians), supplement that with a painting and look to see what Era/Civ you could grab to finish it. Overall I agree with your assessment that it is clumsy and wish it had a more hands-off approach, in that artworks should go into the building that will get the most Tourism automatically. Sadly, you've just gotta go back and forth between those two screens. It's almost like Theming is a secret known only to a percentage of players because of this.
Wish I could be more helpful, but once I got used to the interface and established what I needed to remember, it was a non-issue for me. Wonders take priority for theming, then museums, and I don't worry about any art that is in a building that doesn't have theming - it is just a holding place for swapping things around to get Theming Bonuses.