This thread is a little old I know, but I'm putting my two cents in.
I think it's 15 seconds. It's way too little time, considering that Bovada does not give you an easy way of making 2/3 or 3/4 bets. As I am slightly retarded, 15 seconds is not always enough time for me to do the poker math that I need to do, as well as deduce what my opponent has, in order make good decisions. I often feel as if I barely have enough time to make the bet, and often don't bet what I would like to bet, as I don't have enough time. I stopped manually entering bets at Bovada after once placing a 22.2 bet when I meant to do a 2.20 bet. Of course my opponent had AA, and I lost everything.