Unfortunately, there were many Jarmans in London at this time. I don't think there's any connection. Have you got the birth and relevant marriage certs and checked the IGI yet? The only contenders in the IGI appear to be Thomas born 1834 (Beccles, Suffolk) son of Robert Barnet Jarman. He might be yours, having a middle name was quite unusual.The IGI doesn't cover all registers of course. Good luck.