letting sand and cement render cure before tiling

[Albumen]

I've just finished the last coat of sand and cement render in my bathroom, which will be tiled over.

I'm probably going to use some sort of membrane based tanking material, then tile.

As I understand it, it's best to use a cementious type adhesive for the membrane.

In which case do I really need to let the render fully cure? If what is going on to it is cement based, isn't it a bit like adding onother render coat, chemically speaking.