Paul, I suppose this is excactly what you are looking for:
ROBERTSON, K. (2003): The Perfect Shoot: Mini Edition for Africa. – 126 p., figs.; Long Beach, CA (Safari Press).
of more general nature and for plain wildlife watching is this one:
HUNTER, L., RHIND, S. & ANDREW, D. (2002): Watching Wildlife in Southern Africa. – 349 p., figs.; Melbourne, Oakland, London, Paris (Lonley Planet).
If you have any chance to get yourself a copy of
CHENEY, C.S. (2000): Bowhunt Africa. – Vol. I - Vol. III
this would be the most comprehensive work on bowhunting southern Africa - at least I know of.