@Dan189
You'll have to list the bathroom officially as 'shared' if it's also accessible to another guest.
Though you can elaborate in the description.
My take on this? I'd have one room with private bathroom at a higher price. Having a private bathroom as guest for me isn't about having a dead bolt to keep another person out while I'm using it, but not having to face another stranger's head and/or body hair, toothpaste and other residue.
If I understand the situation right, then the other room would have to share a bathroom with you?
You could price that one lower and make sure they understand it's without a private guest bathroom.
From what I've seen on the forum posts bathrooms shared by two or more sets of guests the happiest situation do not make, and there seems less involvment re. proper tidying up after themselves.