The FRTOL is a separate licence and is not a pre-requisite for the issue of a JAA PPL.
The JAA PPL can be issued without RT privileges however, as you have to pass the Communications written examination before you take the PPL Skill Test, and have to demonstrate that you can use the radio in order to pass the PPL Skill test leaving it out doesn't make a lot of sense.
If you take the FRTOL at a later date you will have to pass the practical test and the written test again if it was taken more than 12 months earlier.
If you do not have a FRTOL you cannot operate the radio in any State that requires such a licence. i.e. all except ITU Region 1 the Americas.