In my experience it's priority boarding at the first check at the door then down the ramp at C gates and filtered into Y bus there. I've never had a J bus when flying Y, and that's as Gold where there is no ambiguity about priority boarding.

In my experience at GVA and DXB as a Gold and now as Silver, it's the Y bus. One reason seems to be that the Y bus boards (for a 777 at least) from the back of the aircraft while F/J uses the front stairs.
Understood, but I doubt GVA falls into this category. While not nearly as big as DXB (LHR, AMS, etc), it's a reasonably sized and recently renovated airport with all the bells and whistles. There were, for example, 8 check-in desks for the single 777 flight, with two for J/Silver/Gold and one for F/Plat; these weren't very busy when check-in opened, while the queues for online check-in and regular Y were quite long. As a Silver (and previously Gold) I have no complaint about check-in, just the boarding process.

I should say that is true for me too. It was only on the one instance where they were having folks wait for the special bus that it was offered. In that case I preferred to board immediately anyways. End result is I've also never had anything but the Y bus for Y tickets despite status. Not saying that it should be different either.

I don't understand all the fuzz about priority boarding for F/J.
I prefer to board last, so that I can maximize my time at the lounge.

This said, I fully understand that Plat/Gold flying Y want to board first, before the horde flows in.

As far as outstation check-in counter is concerned, it seems that special Y cases are more and more treated in F counter.
Last week, it was clearly two family ticket holders on standby negotiating a way to get to their final destination during this very busy holiday period, while two F pax were waiting behind ...

That's an issue with the outsource company though - always worth a quick word or comment in to flag it up, imho.

Agreed , it is a F dedicated counter not a " send all your problem paxs" counter. A few times now at CPT i have waited longer in the F line then the J line due to passengers having issues with their tickets , ended up being taken to the economy line :rolleyes::mad:?!

Well, the two ladies were not wearing leggings ... so, really nothing to complain about :D

I haven't actually counted the bus seats, but I also believe the J bus has exactly 42 seats (as does the 77W). There might be extra seats when two buses are used for the 388, but probably too much trouble to work out how many Golds and Plats versus seats in J buses available. Certainly no room in F bus for Plats on some routes.