Prime Plasterboard before tiling

[Flintstone]

Priming it won't hurt. I always prime every surface, unless it's totally none porus.

 

[Dumbo]

Priming it won't hurt. I always prime every surface, unless it's totally none porus.

Same as .

 

[Shooter999]

Thanks all. I'll prime all surfaces.

 

[Time's Ran Out]

From the original post if your stripping out the old plasterboard and tanking and using 600x300 porcelain, why not just replace the walls with Wedi boards and do a better job!
For a shower enclosure the extra cost cannot be much but for peace of mind it must be cost effective.
Plasterboard+primer+tanking kit v Wedi + tape.