Since the name Bongiovi is a European name, i.e. Italian one, of course Bon Jovi sounds somehow European, since it is just a slightly change of Bongiovi. But a lot of names in the USA sounds European since there are loads of people with European roots. It's just natural.

I don't know what Bongiovi means but it doesn't mean Good Jon. I heard it would mean something like Good life but I cound't find a translation for Giovi on the net. Why should the name hindered their success? I mean they are one of the most successfull rockbands, you nearly can't have more success as a band than they have. And when you think the name sounds strange, a band with all male members calling Queen is way more strange.