The rules on earths have just been changed. So I would not think you will need any earths but I am careful here forgetting about rules ask yourself are there any metal items which however remote could bring power into the bathroom.
Can for example a standard lamp fall in one room onto a radiator and in doing so make a bathroom radiator live?
With out seeing your installation therefore I would not like to give an answer.
have to be carefull on this one.........
earth or supplementary bonding is still required in bathrooms under certain conditions.you have to understand what the earting is for to get to the answer of this question. take for instance that if the bath is metal and you have copper pipes they could become live at another part of the house and then.......well