No. Generally, you can assume that a mod won't work online. Hot Seat plays like single player (when it comes to turns and code et cetera), with one or more humans instead of AI's. Multiplayer is different, and a lot of code needs to be made specially to account for that.
If this mod only adds XML things, however, then chances are it'll work online. But, try it out - can you launch an online game with only you and AI's? If that works fine, then it should probably work fine with you and another human as well.
I might be able to contribute expanded city lists and great people names to that (I'm in the process of adding all cities and great people names of Civilization III, V, and Rise of Nations - and possibly Empire Earth? - to my own mod, though it takes a lot of time because I want to read up on all of them ). Do you have a link to this mod, perhaps?
I'm afraid not, but it's on the forum in the mod pack list.