In the 1911 census there were two houses in Bennetsbridge with Fennellys.(It's still a very small place!).One was at No.1 housing John Fennelly, aged 58 and his wife Marey aged 55 and 4 children. At No. 5 there were Patrick, aged 57 and my grandmother Catherine aged 29. There are 181 other Fennellys in other parts of Kilkenny!
What then complicates is that Family Search does show a James Fennelly born at Bennetsbridge, with parents John and Mary, but not until 21/8/1879 - ie 11 years after your great grandfather's estimated dob and surely too young to marry in 1890.Of course Family Search dates may be wrong and the Irish in the 19th C did seem to have a very limited range of names they chose from!