Unfortunately I have no date of marriage. I can only assume that John Hanson married a" Anne Holmes" as his eldest daughter and son carry the name. Their children are born between 1798 -1810. As I said John Hanson's son John was an agent for Thomas Greg of Ballymenoch It seems he also lived at Ballymenoch House as his wife Jane died there in 1860.
John Hanson jnr was a successful business man in and around Belfast. His brother James Holmes ( as I have recently discovered) moved to New Zealand and was part owner in several gold mines. He took his unmarried sister with him" Anne Holmes Hanson" who died unmarried. a third brother George was a presbyterian minister and retired to Bray Co Wicklow. The Coates connection was through John Hanson jnr's daughter Frances who married Arthur Hill Coates of Bangor.
James Holmes Hanson died in NZ in 1886. Three of his children carried Holmes as their middle name. I suppose the mystery will continue until we can find some concrete information .
Unfortunately marriage dates, as you know,in N I around 1800 are almost impossible to find.