Bus stands are not in themselves an issue, but there should be a separate bus for F pax. I arrived in FLR once off a LX (operated by Helvetica) E190 and they had a separate bus for the six J pax; and RJ had a separate bus at AUH for the 3 J pax. If these airlines can do it for what is basically an intra-Europe premium cabin then SQ can certainly do it for 4 F pax.
I have found the soft reception for F at SQ outports quite varying. The high water mark for me was at CDG recently, where the station manager was hovering in the corridor between the BP scanning point and the airbridge (if the plane is at the right stand at CDG-1 SQ can use three boarding gates for the 777, one for F, one for J, one for Y, even though only two airbridges are operational) waiting to intercept us, take our bags, take us on board and introduce us to the crew etc. Not that this is necessary, but it certainly made us feel special!