The first scenario you described (placing pawns on light squares, to make the opponent's LSB "bite on granite") is not something I generally think about. There is usually much more to consider in the position, and making my opponent's bishop bite on granite is not much of a improvement to worry about - UNLESS I'm trying to trap that bishop.
IF I'm trying to trap my opponent's bishop (or trying to lock it behind my pawns, restricting it from the rest of the board), then I'll definitely consider using my pawns to do so. But if not, I generally won't move my pawns just to slightly limit the bishop's scope - since there are usually more important (and more immediate) things to be addressing.
The second scenario you described (placing pawns on the opposite color of my opponent's only bishop) is something that I consider, and something that I do often, once the game reaches the endgame phase. The reasoning is to simply make the bishop feel "useless" - having no pawns to target, as if it's stuck on the wrong-colored square.
Though, again, there are often other considerations in mind (tactics, for example), which must be considered first. Sometimes, tactics will require your pawns be moved in a specific way, and any such notion of colored square complexes must be disregarded, to address the more immediate needs.
(Hope any of that helps.)
I see many masters tell chess players to put their pawns on light squares, for example, to counteract an opponent's light squared bishop after trading off their own light squared bishop, which makes sense. But then later they put all their pawns on dark squares so that they can't be targeted by the opponents bishop, which also makes sense. What I don't understand is when I should start putting my pawns on the opposite colour square to the opponent's bishop? Can someone high-rated please explain (2000+ preferably, no offense)