The authorities and local families are continuing the search for him, as well as for 28-year-old Mushfiq Daniels from Surrey Estate, who went missing while teaching English in that country.
Bothma went missing in May, just before he was about to fly back to South Africa, while Daniels disappeared in July.
Both went to Vietnam to teach English and were last seen in Ho Chi Minh City.
Santjie Dixon, who has cared for Bothma since he was a minor, said the families were no closer to finding the men.