I dont know if there is any connection between your Beynon Jonas's and mine but seems unusual combo of names.
My grandmothers cousin was called Cecil George Beynon Jonas.
His mother was Mary Jonas (nee rickards) who was married to a George John Beynon Jonas.
Mary and Cecil (born 20 Dec 1888) are listed as 'visitors' staying with my grandmother (age 3) and her parents in the 1891 census York England.
George is not listed with them at that address.