I understand that the material is waterproof, but is it recommended for full bathrooms where there would be a tub and toilet? Not as much worried about the material, as I am about water getting underneath the material.

The COREtec planks can be installed in full bathrooms with a tub and toilet. The locking mechanism on the COREtec is very tight, you should not have any issues with water getting under the material through the product. You should however consider using silicone caulking where the tub meets the planks so that you do not have an open are where water could potentially get underneath.