The Internet seems to have been designed specifically to be such a huge boost. As is recognised by so many on the forums and no doubt by the Firaxis groups, by the time you get the Internet the game is more or less decided. They put in the Internet with all civ's characteristics to allow anyone the chance to have their GA where they missed it before. Chances are that if you haven't had your GA by then you are behind enough that it will act as a way to attempt to improve your lot before the inevitable game end. I haven't built it once in my games yet, but it seems to have been designed so powerful intentionally.
As for the culture improving WoW, remember that in the Double Your Pleasure mod in PtW, the Pyramids add an Obelisk (culture value 1 ) to all your cities. If a WoW can not have the characteristics of increasing culture for a certain improvement, then a reasonably close idea would be to add a Wonder that adds an improvement to all cities that only produces culture, like the Obelisk. The only issue is that you needn't build anything beyond the WoW to get this bonus to culture in your cities.
As for the culture improving WoW, remember that in the Double Your Pleasure mod in PtW, the Pyramids add an Obelisk (culture value 1 ) to all your cities. If a WoW can not have the characteristics of increasing culture for a certain improvement, then a reasonably close idea would be to add a Wonder that adds an improvement to all cities that only produces culture, like the Obelisk. The only issue is that you needn't build anything beyond the WoW to get this bonus to culture in your cities.
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