Japanese Torii Gates Wonder should give a multiplier to the XP. Some time ago it was buffed from 1.5x to 1.6x. However I noticed that 1.6x is applied only when you are creating new units. In case if killing enemy units old 1.5x is applied (for example 15 XP for every killed villiger or 75 XP for killed falconet).
Is it a bug or it is expected behavior? In game description I can see only information about 1.6x multiplier. I can provide screenshots or video with more info if needed.