I think in order to rank well in your targeted area like za, you will need to link more in sites specifically catering to za. International sites or links would be your target if you want to rank well in google.com...
It is due to different data centers.Google has set up different -different data centers for countries.So due to data centers Google ll show your country results first than other web.It ll always show you different results in your area and web.So if you are targeting your area,you can use Google local places to get rank well in your region.
The first category is relevant for a geographical area, whereas the other one is more general. The idea is that if the former better suits your "local" targets, the latter is dedicated to returning the best worldwide results to your query.