Hi Chris - the two surnames seem to have different origins, but it's possible that the spelling of one changed due to error at some point...? It seems strange that my Burton ancestor with links to Solohead and Galbally who emigrated to New Zealand around 1875/6 would not be somehow connected to your Bruton family with similar links. My John Burton married Bridget Mahoney in Galbally in 1859 and they had several children in Ireland before emigrating to NZ.
Do you know what ship your Brutons travelled on? Family stories regarding my ancestors suggest they came over on the Fernglen, but I haven't found them on any passenger lists to date. They settled in the Blenheim area.