There is no such thing as "One World upgrades".
AA/BA/IB have a cross airline upgrades subject to t&c's. A lot of t&c's!
Look here
http://www.flyertalk.com/forum/ameri...aster-thd.html
If you have AA miles you can, subject to availability, get an award flight on a range of airlines to South Africa. Try BA, QF, QR, EY & CX (but have not checked if all fly to RSA)