If you would like to surprise people you may have 1920s bathroom tile designs, which is not very common. This style uses many industrial ideas, for better understanding you must take a look at some photos and pictures.
Yet, since it is going to be contemporary bathroom resembling old time then you should not limit yourself in the material selection. The most important is to follow the main idea of the bathroom design. The tiles are usually made from ceramics, they are of standard size and there are no bright colours. Usually the colour scheme is not rich and there is less expression in it, quite often you are offered to use pastel tones. It is possible to have not clear lines but rather formless elements.
The ceramic tiles can be combined with some other materials, moreover, the certain elements can be integrated in the tiles. That could be usual wall tile with unusual pattern.