I would agree that all boarders have equal access to the facilities but this situation seems kinda different. And I agree, I need to talk to the owner and see what the deal is.
If things have changed - then yes you need to talk to the owner. However, if this is the set up in place prior to moving your horse in, it is not the BO's issue.
Very frustrating as a BO to have boarders want things changed after they move in.