There are a few experimental SAB hop cultivars that are very sought after by local brewers, but generally it's the common SAB hops (S. Promise, PIH blend etc.) that are used just for bittering. I'd say the majority of flavour and aroma hops being used in the SA craft industry is imported. Same thing for grain: most brewers are using SAB's pale male and black malt, but the rest of the specialty malt is imported (to my knowledge, it's mostly Weyermann and Beztmalz with some Castle Maltings and Thomas Fawcett as well). Brauhaus, for one, uses only German malt, even for their base malt.
When it comes to local craft lagers and Africa Pale Ales, I wouldn't be surprised if many of these are SAB only ingredients, but bear in mind that they likely have no maize added like SAB beers.