I have been twice, both times with a party of four, to The BoomBar Crouch Hill London N4 You can search for more details on the net. On each time the food was excellent (not only South African but a lot of the meals are African as well). The wine menu is good and not too overpriced, although they have a spec ail £30+ wine menu for some of the finer South African wines which are not available in off licenses or supermarkets. Each time we had a wine from the normal list called UitKyk - pronounced ate-cake :-) meaning outlook.
London, United Kingdom