Ok, but yea it won't stick. The wallpaper would probably slide off it and it wont dry probably.
Yes, ofcourse you can put wallpapers over tiles in a bathroom for that you need to use sanitary (wipeable) wallpapers with is excellent in water resistance. The best option is to use vinyl wallpaper. If you want to increase the adhesive strength of wallpapers in bathrooms then you can also add some (like 20%) dispersion adhesive to your regular wallpaper paste this can takes a long time to dry and also harden than wallpaper paste.
Bathrooms are under the category of “damp rooms”, where steam comes from hot baths and showers which can increases the air humidity considerably. For that the correct ventilation in bathrooms is very important.
There are three methods of wallpapering tiled bathroom walls using beautiful patterned wall décor which will transform your old bathroom into stylish and new looking bathroom.
Method 1: You have to Remove old tiles, re-plaster the wall, and apply wallpaper.
Method 2: You can also Smooth over tiled walls, and then apply wallpaper which is also a great option.
Method 3: One more thing you can do is Mounting the gypsum plasterboard from a surface for hanging wallpapers.