Make sure the wainscoting/tiles are high enough.

Vinyl wallpaper is pretty durable and can be washed easily. It's usually just as washable or even more washable as a washable paint surface.

It should be fine, it's really the humidity from showers that will ruin the wallpaper, not a bit of splash from someone washing hands.

Vinyl wallpaper works in water areas well, almost as good as tile walls. Brewster Wall Coverings has a lot of updated looks. Love the Kenneth James books.

I usually roll my eyes at hesitance to use wallpaper in bathrooms, since I have used it in 6 of my own bathrooms over the years with no problems.

But guess what--the wallpaper over the vanity is beginning to show signs of deteriorating from splashed water, even though there is a backsplash. But, considering that it was installed in 1979 and has been used daily since then, I think that is normal wear and tear. I still have some extra paper and plan to mod pudge it onto the affected area, as I have done where Kitty has clawed at the paper.

Powder rooms are particularly suitable to show off beautiful wallpaper. In my opinion.