Designing Kitchens and Bathrooms - Shower wall options/Wainscoating?

We are wainscoating the the bottom 4 feet walls of the bathroom around three walls with a pre primed sections which we will then paint enamel. My question is, can we continue the wainscoating inside the tub enclosure and throughout the shower walls to the ceiling? I think that even if we primed, painted and calked there would be the risk of water damage and rot but my partner says that it would not. I have seen painted wainscoating above stand alone tubs but not in a tub shower. I'm not really interested in tile because it is a small bathroom and we think that it would not blend in with the vertical lines of the wainscoating. If this is not possible, does anyone habe any suggestions? A pre molded shower surround in out of the question. I haven't seen one yet that I can live with. Is there a wood look vinyl wainscoating made that could withstand the water and humidity? Or other suggestions besides tile or surrounds? Any suggestions would be appreciated. Thank's, Pad

Do not put wainscoating in your shower. Big mistake. Your partner is wrong, Nothing can seal wood that good. You might think of shower paneling with a wood look. It comes in many different decorative designs.

Jack is on the mark. Mildew city.