regs wise bathrooms. pools  and showers are special, WCs and hand basins are not. So unless the supply is TT, given the cable is protected as you indicate, then an RCD is not mandated.

That said, the environment of the public loo, especially the sort that is open all night, may be more hostile than most, and if you think it is the kind of location where it is likely that things will be vandalised, or covers removed and lights stolen then an RCD or RCBO cover for almost everything starts to look prudent.

Mike.

You may recall an incident in a McDonalds Belfast maybe 20 years ago when a young woman lost her life after making contact with live parts of the hand dryer in the toilet. The unit had been vandalised and management failed to attend to the issue in a timely way. As a result McDonalds fitted RCDs on dryers in all their restaurants across the U.K. 

For me, vandalism is a foreseeable possibility in places like public toilets so if equipment is operating at dangerous voltages then at the very least, RCD protection should be put in place.