On the older bikes you had to remove the caliper and hang it up higher to bleed the last of the air out.
I have no issues with the V4S rear brake, it could be that the bike has sat around for a while and the rear calliper pistons have seized? I would have thought the dealer should have checked that in any case, easy to check when you take the rear wheel out which is also easy to do on a V4S Multi. The brakes are linked front and rear so something very wrong if it doesn't work at all.
Likewise I’ve not had issues with the rear brake on the V4. Let us know how you get on, good luck Might even be worth starting a new thread rather than adding to this one.
Yes, there's something very wrong, I ordered some new brake pads also when they come in, we 'll see what happens.