Thank you both for your reply.
Yes 'Bonny's' mother Elizabeth Ambrose married Michael Hood in 1863 later remarried in 1877 a Thomas Yates (& had 3 more children:Thomas, George & Annie)and following that in 1893 married Frederick G Thornton!
I don't think we had any luck tracing them on the 1871 census. But did manage to find 'Bonnys' father Michael Hood on the 1861 census as a RM on HMS Ceasar. Also on the same ship is a Robert Ambrose, who we assume is Elizabeth Ambrose's father.
Least if no-one can find a marriage or a death for a Bonny Hood, it seems like we are on the right track linking him to Frederick Bonnyhood, its just a shame we cant really prove it!
Thanks again