I do it all the time! In fact, my main floor 1/2 bath has Mary
Englebreit fabric on the walls!
Just put your fabric down in a wallpaper tray that has liquid starch in it. squeeze out as much as you can and then put it on your walls...smooth out all wrinkles...as it dries..it affixes to the wall.
I used a sheet on a bathroom wall once..it stayed up without any problems for several years..with the shower steam and all!
Granted my 1/2 bath doesnt' get as steamy..but it has been up and withstood my grandchildren for 9 years!