I'm inclined to agree with twinklemegan. It would be better if schools looked at, and dealt with, "sticking points" rather than requiring a label, be it SN or G&T, before any child gets individual attention.
When DS1 (now 12) was in reception, the teacher actually noticed he had an aversion to writing and arranged for him to do some work with a classroom assistant to encourage better (and longer) writing. That wasn't to do with a G&T label, but was probably the most useful piece of intervention he had. Now he's officially good at writing - indeed, he was involved in the school magazine writing exercise mentioned by clerkKent.
In Year 1 he went to G&T sessions with another boy in the class, in which they did rather nebulous and ill-defined tasks, but at least it got them out of Guided Reading. A while later, the G&T teacher retired and was not replaced, and thereafter there was rather patchy G&T provision. The local authority runs some holiday G&T activity days which are quite good fun (so I'm told by DS2 and DS3) but don't sound wildly inspirational. They also run a course of Saturday morning maths classes for a boy and a girl in Year 5 from each primary school in the borough; DS1 found that more worthwhile.
A few things to add to what clerkKent has already said - there was a Year 7 G&T (later expanded to others interested) Carnegie shadowing group, and a Maths. competition (something to do with cars) that was open to anyone interested.
None of the above has left my children with overinflated egos; I wouldn't allow that .