Right now, if you queue up a wonder, you keep the AI from having a chance at it.
My idea: ch0ange how wonders are built completely.
Wonders should be based on the first to build a regular improvement, with a delay of x turns.
Merchantcross Bazaar would require a Tax Office
Great Mill would require a Mill.
Ereog's Tower would require a (Temple of Essence?)
This solves the building a wonder not to get anything problem, and makes it fairer for the AI. (all you'd need is some AI code to prioritizing rushing of those buildings if the AI believe they would be the first to build it)