Have you searched for the Llewellyn Davies listed below in the 1891 and 1901 census?
1881 census 22 Wind Street, Neath, Glamorgan
Eliza Davies, age 73 born Ewenny, Glamorgan, coal miner's widow
David Davies, son, age 36 born Neath, Engine smith on railway
Griffith Davies, son, age 31 born Cadoxton, engine fitter at brewery
Llewellyn Davies, son age 29, born Cadoxton, engine smith, unemployed
Ann Evans, servant, age 21, born Neath, general domestic servant
It looks like you have the correct Llewellyn Davies (from Penrhiwangharad), but it would be wise to check out this other unmarried Llewellyn Davies who lived on Wind Street in Neath not far from Elizabeth Hopkins Hunkin.
The Davies family from Penrhiwangharad is my family, so if you have the correct Llewellyn, we are distantly related.
Best regards
Richard Davis