I am by no means a pro but if you pin a live bonnie you have a chance of getting tuna,wahoo or a saily.You also stand a good chance of getting a blacktip!
Good time of year for the above mentioned species (Sailies, Wahoo, Couta, Tuna) you can pull plastics as well.
A live bonnie is key there though if you want a trophy pelagic.
Remember the rules regarding the Aliwal crown though so go check out www.fishingcorner.co.za and download the south coast marks particularly the crown points which demarcate the boundaries you are allowed to fish around there.