Yes, it is possible to fit underfloor heating within a wet room. It is an especially prudent idea to introduce underfloor heating to small wet rooms, as it will negate the need for the likes of heated towel rails or bulky radiators.
Underfloor heating is ideal for keeping the space at a comfortable temperature all throughout the year, but will also help the floor in a wet room to dry out at a quicker rate as well.
For further information surrounding this, and all sorts of other wet room inspiration, take a look at our blog, How To Introduce Small Wet Room Ideas To Your Home.