When I call and shoot the 8 ball and it goes into the called pocket but the 8 bounces off opponents ball before going in, is that still considered a win?
From WPA rules, the general rule for all types of called shot games contains:
1.6 Standard Call Shot
In games in which the shooter is required to call shots, the intended ball and pocket must be indicated for each shot if they are not obvious. Details of the shot, such as cushions struck or other balls contacted or pocketed are irrelevant.
Further, for 8-Ball specifically, the ways to lose are detailed:
3.8 Losing the Rack
The shooter loses if he
(a) pockets the eight ball and fouls.;
(b) pockets the eight ball before his group is cleared;
(c) pockets the eight ball in an uncalled pocket; or
(d) drives the eight ball off the table.
Your scenario doesn't seem to describe any of these (see 3.9 for all the standard fouls), so it should not cause loss of game.