likair: It's up to your Avaition Authority. In the UK you could use a SA PPL for 'hobby' flying in Uk aircraft without any other paperwork. Other countries might want you to perhaps 'validate' it first with a little test and a ground exam (but retain it basically as an SA PPL but valid for that country), others might want you to convert to their local licence. (I think Malta is a 'JAA' state now isn't it so to actually convert is possible with tests and ground exams)
When asking your aviation authority try and be extremely clear about the questions and answers - one question is can you fly on your SA PPL (or what do they want you to do so you can), and another completely different question is how to convert