I am not sure, but I think your ancestor must be the William S. Wellons who was the son of Charles Wellons and his second wife, Bethany Gerald Jones.(married March 17, 1786). This William S. Wellons was living in Johnston Co. in 1818 when he received a land grant from the state of N.C. This William had brothers named Wesley Freenman and Charles Marmaduke, and one of his nephews was called Larkin, so it would appear that your ancestors belong to this branch of the Wellons family.
Charles Wellons, born about 1762 and died 1840, is the son of Charles Wellons and the grandson of the earliest known Wellons, John and Annamariah Wellons.