Oh Oriel so glad you spotted that!
Marriage was 1812, 22 August.
Thank you for those suggestions, there is a Celtic Ancestry which suggests the following:
William Thomas b 16 October 1788 of Fferm Craig Begelly
father William born 1754 Fferm Craig, Begelly, died 30 October 1830 Castell Nedd, was married to Ann Phillips b1761. I have, however, found out that there is a family bible which disputes the name of Williams wife. Details also that William was agent to Lord Milford, in 1794 employed at colliery 12 miles up the vale of Neath.
Father of William b 1754, was Griffith Thomas b 1730 of Rock Farm, mother Elizabeth b abt 1730 Dyfed.
This is the end of the details.
My reason for posting was finding that the wife of William was not Ann Phillips, and I decided to check the details for real.
Jon, William b1788 became a publican census 1841, but on his son Richards christening in 1815 his occupation was mariner. This family were the founders of Richard Thomas (& Baldwin).
I hope this is not too confusing...