you don't have to use cherry, but a wood cabinet would be nice to break up all the white in the bathroom. It would not make it look dark at all, but would add a focal point.

I don't think a cherry cabinet would make the room look smaller. It really depends on what else you are doing in the rest of the bath.

I am taking out the hot tube a putting in a bench that will have storage inside which I am thinking will be similar color to the tile

The flooring tile is a creamy limestone named French vanilla from Speartek , I am planning for the top of the vanity to be perla Veneta which is a creamy quartz

i am just worried that I will have a lot of cherry close together due to the two pieces of furniture on either side of the doorway into the bathroom. Maybe they will compliment each other.

Thoughts?

don't ever worry about coordinating built-in fixtures with furniture--that can be changed if need be. A wood vanity would look great in your space. Consider a darker or lighter stain for it, so it doesn't seem so matchy to your furniture. Once you are in the bathroom, you won't even see the cherry furniture in the bedroom.