Hi jamesegrant, as BrianDromey mentions - LX or LH might be your best bet, flying out of one of their hubs i.e. ZUR for LX. Discussion on this topic can be found at the following thread : Finding 4 redemption seats . Something obvious, but a look at the routemaps for LX can reveal locations that you won't necessary think that they serve.

LX have not yet released redemptions on their new ZUR-SFO route but from a booking I did recently for 6 pax - availablility into LAX from ZUR is good for large group - perhaps not always on the weekend.

All the best with the booking !