I'd recommend keeping the enlarger out of the bathroom if at all possible. The bathroom is the most humid area in the house and is prone to some nasty odors at times.
When I first got my enlarger I too placed it in the bathroom but quickly moved it across the hall to a large and otherwise unoccupied corner of the bedroom and taped tow large black 3mil contractors trash bags to the L-shaped corner to absorb any stray light from the enlarger. Perfect: out of the way and away from excessive moisture. When I expose a sheet of paper I place it in a paper safe and walk it across the hall to the bathroom where the developing trays are set up, close the door and process the paper. I have a Thomas safelight set-up in the bathroom and a small 5x7 safelight in the bedroom which gives me just enough light to see where the box of paper, easel, and papersafe is. When the prints are ready for final wash, I bring them into the kitchen where I have a 11x14 Versalab print hooked up in the sink. For prints larger than 11x14, the final wash is in a 20x24 Gravity Works washer in the shower.
I also have a large vanity mirror in the bathroom which I cover with a large black trash bag when unloading 4x5 and 8x10 film into Jobo drums for processing or when tray processing sheet film. Any light that enters will eventually reflect off the mirror. I even remove my white T-shirt at times. Except for the entry door, my bathroom has no other way for light to enter and I block it completely. Yet I can usually barely make out my moving fingers in front of my face.