Sorry for this belated reply; the fact is that I just saw your message by pure coincidence. Let me tell you something, here is Saudi Arabia are against online teaching certificates, however, online degrees are fully accredited in Europe and many other parts of the world. Here, in KSA, they ask for the Cambridge CELTA which the most reputable teacher qualification -according to employers-. I did two online courses through the ITTT, the one you mentioned, their courses are hard and demanding, but very useful , gripping and riveting at the same time. Also, they have what is called blended learning, i.e, you do some chapters or units online and then followed by on-site TP Teaching Practice in Phuket, Thailand. I don't guarantee doing only the online phase of the course can secure employment. I suggest you do the Cambridge TKT (Teaching Knowledge Test) through the British Council school in Riyadh; this would boost your CV since you are considered a native English speaker for South Africa. Contact me for details.
I hope I helped a bit.