We're doing an Africa trip in December on a oneworld award. We were able to book business (or whatever BA calls this class there) on two intra-Africa flights. Mostly, we found plenty of availability for coach class, and ended up having to stay in Kenya for 2 extra days to get business to Johannesburg. It's a 4-1/2 hour flight from NBO-JNB, so we held out for "better".