Inside a bathroom they are usually not but best to figure it out first. You need a good look at the floor joists above.
If they end or join over the wall it is load bearing. If they run in the same diection as the wall it should be non load bearing.
You may find a plumbing vent stack in one.

 

Probably not load bearing, but the plumbing is in that wall. The vent is a pain in the butt to move.

 

We wanted to get to the plumbing. Might do a half wall on the vent side, does that duct come from the bottom or go up the wall too?