Been a few years now and I have a bit more information.
Marriage certificate dated 5 May 1888 at Tabernacle Chapel, Pontardawe:
Thomas Benjamin JOHN
Age 23 years
Batchelor
Occupation: Tin furnaceman
Residence at time of marriage: Graigllanguick Llanguick
Father: Benjamin JOHN (deceased)
Father's occupation: Tinman
Miriam HUGHES
Age 21 years
Spinster
Residence at time of marriage: Alltwen Killybebill
Father: Joseph HUGHES
Occupation: labourer in Iron works
Witnesses: Mary DAVIES and James HUGHES
Minister: John Thomas DAVIES
Registrar: Thomas REES
Still baffled as to how to find out more about Thomas Benjamin JOHN's parents....
Also trying to find out about son, Thomas B JOHN who is listed on 1891 census as aged 4 months. He is not on the passenger list when they went to South Africa. I can't seem to find a birth or death listed anywhere.
Have also spoken to my 2nd cousin recently and the male cousin my mother visited many years ago was Meirion Mainwaring, he would have been born about 1939. My cousin thinks that his mother was Blodwen JOHN but we don't know how they are connected yet. I've asked him to try and find out from his mother who is now in her 90's.
Many thanks,
Sue