Welcome to the forum. welcometomyturbodies
Well VW do a bike rack well the actually do 2 of them. One that hangs from the roof bars which looks terrible and one that fits the tow bar.
Bike lift max weight 20Kg - 4D0 071 128 D - Â£257.50
Bicycle bracket - 6Q0 071 128 - Â£90
Bike carrier to tow hitch (ball head) for 2 bikes - 3C0 071 105 A - Â£387.50
and Bike carrier to tow hitch (ball head) for 2 bikes - 1T2 071 105 - Â£375.50
They also attach a set of tail lights to them.
I've just seen a picture Accessories for the Golf Plus
. Though the roof one is different again.