Hmm, 4 different sets of wonders could be 4 "bonus continents".... To own a bonus continent you would need to own 1 of the different sets of wonders (eg;. all of ancient wonders)
Say Map of world, where each wonder is placed in its country. Owning Europe does not give you a Bonus, but owning (Giza Pyramids,Hanging Gardensof,Babylon,Statue of Zeus at Olympia'Temple of Artemis at Ephesus,Mausoleum of Maussollos at Halicarnassus'Colossus of Rhodes,Lighthouse of Alexandria) would give a bonus.
There may be lots of countries which will always stay neutral, as no one will want them, such as Age of Realm, or age of Merchants... Other countries would have 2 or three wonders placed on them (divide countries up into enough states to allow 1 wonder to be placed in 1 state-- USA needs one state to hold Statue of Liberty, one for The Golden Gate Bridge, one for the Grand Canyon)
Interesting thing is... in above scenario, holding USA would give no bonus, as Grand Canyon would be a different "bonus continent" as it is a natural wonder, while other 2 are Modern Wonders..
A Great idea...

