Yes, of course. You can hang canvas painting in any room including bathroom. Why? Because the humidity is intermittent and canvas is very durable. Think about the humidity in New Orleans. Average humidity of 74.5 percent on a regular basis! People live in there hang canvas painting without any issue.
 
However, due to the special environment in the bathroom, it is not suggested to hang vaulable artwork in bathroom. If you do like the artwork and want it to be show in your bathroom. Get an oil painting reproduction.