in this game of mine, my black bishop is worth a full point :
http://fr.lichess.org/R4vWFAQM/black#54At face value yes, it has more activity potential, whereas your opponent's is basically just a big pawn. It just goes to reinforce my point that we can't assign static values to pieces, especially ones reliant on the pawn structure. In this sort of position your knight is also stronger than his bishop and so if he were able to trade his bishop for your knight it'd be a good trade. (Unfortunately, he does try this but throws away a pawn to do so by moving the knight one move too early!)
However, the engine evaluation still slightly favors White at this point because after protecting the pawn with Qd2 and then exchanging knights, the position will be fairly difficult for Black to open and so that bishop isn't going to do much with its activity. White can probably force more trades and take advantage of those advanced pawns. But it's likely just playing for a draw. Of course if Black retreats the knight it's much easier for White to break on the f file and make his bishop useful again.
So yes, at face value your bishop is worth a full pawn more for that moment, but that's not the entire reality.
#1 Stockfish gives bonuses for things like "bishop pair":
http://support.stockfishchess.org/discussions/questions/600-material-evaluationso effectively, bishops are sometimes worth more than bishops.
#4 Excellent question, and one best answered by engine-engine matches!