Next time it might help if you bothered mentioning a few more minor details, like what color you were playing - instead of letting everyone else having to figure it out on their own. You could have just cut and paste the pgn file into the board editor here, which would have inc all the game details (I usually delete my opponents nm if I won)
He (she) shouldn't have resigned so soon, (as you noted) your 2 connected passed pawns do look imposing but opposite-color Bishops can be very annoying sometimes even vs such imposing odds.
You should submit the game for analysis in addition to doing some of your own.
My oponent placed too much confidence in drawing opposite color bishops.