I'd like to help, but need for you to do a little more research first. It's very difficult to research living people (or anyone born after 1930), because of all the privacy laws. John Henry was a popular name, and many BARTLETTs have it. The spelling of his father's name, Kennith, is unusual so that may be a good clue (although many records have creative spellings in them.
Please try to research and post more about Kennith BARTLETT, hopefully including his birth year and place - if it's before 1930, that may give us an entry into the census records that go back (in the USA) to 1790.
How long has this BARTLETT line been in South Africa?
If you know of a living male BARTLETT from this line, you might want to join our DNA project - just search this board for DNA to find several posts with progress reports and links to get a test kit. A DNA test kit makes a fun, interesting and educational gift.