Hi
I noticed the Marriage entry by chance and I don't really know anything about the BISHOP family, however I had a quick look on the National Archives site and found the entry below - the name here is CLARK. It appears that Mary Elizabeth was a widow when she married James and her maiden name was Venables.
I also saw a few transcribed Baptisms from the Bloemfontein Methodist Church in case you have not seen them
DEPOT VAB
SOURCE MHG
TYPE LEER
VOLUME_NO 0
SYSTEM 01
REFERENCE C69
PART 1
DESCRIPTION CLARK, JAMES. EGGENOTE MARY ELISABETH (GEBORE VENABLES).
STARTING 18660000
ENDING 18660000
[Translation :
VAB - Orange Free State Archives
Eggenote - wife
Gebore: born]
Baptisms
139 BISHOP Alfred John
James McKay and Mary Elizabeth 'Benanbles' of Bloemfontein *spelling
b.1869/08/30
Bap.1869/10/03
195 BISHOP George James
James McKay and Mary Elizabeth of Bloemfontein
b. 1872/04/09
bap. 1872/06/16
228 BISHOP Edgar Arthur
James McKay and Mary Elizabeth of Bloemfontein
b. 1873/06/19
bap. 1873/08/03
318 BISHOP Agnes Hannah
James McKay and Mary Elizabeth of Bloemfontein
b. 1875/03/17
bap. 1875/05/12
355 BISHOP Elsie Emma
James McKay and Mary Elizabeth of Bloemfontein
b. 1876/03/14
bap. 1876/03/16
at parents house
356 BISHOP Grace Mary
James McKay and Mary Elizabeth of Bloemfontein
b. 1876/03/14
1bap. 876/03/16
at parents house
468 BISHOP Gertruda
James McKay and Mary Elizabeth of Bloemfontein
bap. 1878/03/11
Regards
Shirley