I don't know if you have seen this, but there's a baptism entry for an Alfred Bonsor in South Kilworth on the IGI dated 9th March, 1823. The parents are Thomas Bonsor and Elizabeth. It's extracted but would be worth verifying if you think it might be your Alfred, the best way would be to send for his marriage certificate because that should include his father's name and occupation.
BTW, just in case these names ring any bells, the same couple also had Henry born abt 1825, died 1826, another Henry born abt 1827 and William born abt 1821.
Hope that helps!