I take it to mean either "unmetered" or "unlimited".
If Local Bandwidth is "unmetered", then it means that any local bandwidth used will not count towards any usage limits. I think that this was the intent of the ICASA regulations (But please don't quote me on that, as there are many different interpretations). If this was the case, you would pay for (e.g.) 3GB of International Bandwidth per month, and perhaps a small fixed fee for local bandwidth. Once you had reached 3GB of International bandwidth, you would not have any more access to international web sites/internet services. However, you could happilly pull down hundreds and hundreds of gigs of local content, and that would not affect your International bandwidth or the price you'd pay in any way at all.
If local bandwidth is "unlimited" but not "unmetered", then the example changes. You buy 3GB of bandwidth (Local vs. International is irrelevant) per month. Whether you used local bandwidth or international bandwidth, it would eat up that 3GB just the same. Once your 3GB is exhausted, you will no longer have any access whatsoever to international websites or services. However, you could continue to use local websites and services to your heart's content... BUT (!) just because it's unlimited does not mean it's free. You may never be forbidden from using local websites and services, but your telecoms/internet provider reserves the right to charge you for any local bandwidth used after you've reached your 3GB limit. This second option (INCLUDING making you pay extra) is what I believe Telkom is going for.