It depends on what you are looking for. Hardcore poses for bath tubs are somewhat difficult; rooms with bath tubs often have unique ones/unique setups so you cannot do a "one fits all" pose easily. A pose needs room and space to put a camera at, and bathrooms tend to be cramped. That results in people making a specific pose if they need one, but not for a pose pack.
Shower is a slightly different matter, but then you could just grab any "against the wall" pose you find and modify it for your task. More specific poses, again, will be somewhat unique to the bathroom you used.
To some extend this is also true for pool poses, but those rooms are usually more open, so you have a lot of space.
I'd recommend either making poses yourself, or specify what exactly you are looking for and make a request.