Can You Put Wall Tile Over Wallpaper?

I'm having a really tough time removing wall paper from the bathroom walls. We are planning to put tile on the walls and I wonder if I can just leave the wallpaper on the walls and have the tile installed over it. How do I know if there is a chance the wallpaper will try to peel off at a future time? Are there ways I can test the wallpaper now to see if it is totally secure?
Carolyn