In my humble opinion (I am sooo not a pro), There is a quick fix. You'll need more mud and a good imagination. Slap the mud on the rough spots. Once they're all good and covered, use a smooth damp songe to smooth in some designs. As long as it remains a smooth suface, you can be creative as to the texture. Sand it smooth once it's dry (which may take longer then you think) and give it a good 1 or 2 coats of primer (I swear by Kilz in bathrooms and kitchens). Remember, a smooth surface is what you're going for, Square Eye is 100% right that your bathroom needs slick walls. You really want to be able to wipe them down, and you don't want stuff getting lodged in little crevices (that's how mold begins).
And let us know how it turns out!