This is one of my best bishop pair games. I think people can over estimate bishop pairs - especially if they have given themselves positional deficiencies in order to get one. But more often then not, it comes in handy- you just have to be patient and not swap them off for anything less then a material gain or if it is totally forcing. Eventually, something seems to present itself, all it takes is a little manouvering.
I think it comes down to two things - range and control. Usually, you having the bishop pair means that your opponant can only oppose one of your bishops and the other one has total dominance over its colour squares.
This, in itself, is not a winning advantage but if you pair the unchecked bishop up with a queen (for example) then suddenly you have created a powerful combination. Also, the added bonus is, you can let your opponant scramble a defence to the threats you are making with this battery and then suddenly switch to attacking with the other bishop.