Been with investec for over 6 years now and must say the rewards programme is nothing to write home about. You get 1 point for every R10 or R12 you spend and the points do not amount to much. Example you need 7500 points for about R250 in value. Its not nearly as beneficial as FNB ebucks for example. By quick calculation the value in comparison to ebucks is about 1/3rd.
I have just opened an FNB account for myself and the wife so will keep you posted in terms of those benefits, but based on what I have seen with some members of my family you can score an insane amount with Ebucks including those 40% discounts at Makro etc which just don't exist elsewhere.
Hope this helps!
Regards