Hi does anyone know whether the 12+ for Bucks CEM or GL please? Thanks

I believe it is still CEM. Looking at posts from this time last year that was certainly the case then, although it may have changed. Some schools conduct their own testing, so have a look at the BCC website (they call it Late Transfer Testing).
Bear in mind that few people get places through the 12 plus (the exception to that is Burnham Grammar, for this year only).

Thanks

Have you had a child go through the 12+ before? I see you have asked about it a few times in the last couple of years. If you have any information, others may find it useful too.