It wouldn't.
Well, it could, but not that easily. You could use python to set the owner of the nearby tiles, but I believe that this would have to be updated every turn which could really slow things down, and it wouldn't actually be generating culture.
There are a couple of modcomps out there that do basically what you want, such as [BtS] JCultureControl: Beyond City Borders, but the ones that wouldn't completely ruin performance are SDK mods that could be difficult to merge with FfH.
I was planning to look into doing so for the next release of my modmod, but I'm no expert in C++ so I'm not really expecting it to work. I've also been trying to get Xienwolf to include it in FF, but he has been hesitant to do so.