Chichén Itzá is very much worth its cost if you have a city with lots of rainforest that you haven't chopped yet. Brazil and Kongo often start in regions that have nice placements for that wonder.
In my opinion the extra card wonders are the better ones, and so is Potala Palace. I like the diplomacy cards and would always like to use more of them. But in my experience, it is also a wonder the AI likes to build.
As the tech tree and civics tree show you, and the civilopedia on top of that, the Leaning Tower of Pisa is not in the game. If there will be an Italy DLC it might include that, but hopefully they chose a different wonder. There's an abundance of structures in Italy that could be used and variety is nice.