Preparation for retiling.

[ivandaviesid63]

Hi all.
Just removed tiles from 2 ajoining walls in bathroom. The bath is fixed so tiles only going down sides of bath and above bath, so really only half tiled wall. Ajoining wall much the same due to big window, so again only half tiled. Removed plaster to bare brick. On the bath wall, in the corner is a separate shower unit with only a shower curtain seperating the fully tiled shower unit from the tiled/plastered wall above bath.meaning some of the plaster was soggy and was removed. Ive patched up removed plaster with hardwall coat. Now i need to retile where i removed tiles around and above bath. Do i need to apply anything on the hardwall before retiling? Or do i leave it as it is. By the way, getting rid of the curtain and buying a glass shower unit when finished tiles. Many thanks for your help and advice. Much appreciated. Ivan.