I have, actually, a very nice person (Matthew) has been very generous with his time in helping me navigate around that site to find what I need.
I think the 'Brunswick' name is really throwing me off - I cannot find anything remotely related to the name. But 'Vaults' is a name used in several places in Bangor. So was this Brunswick Vaults in Upper Bangor a hotel? A bar with rooms? I don't know. But I think I'm catching on that 'vaults' is a quaint way of saying 'rooms'.
I think what is really throwing me off, is why would someone who owns a house in Bangor have his 'place of abode' listed as Brunswick Vaults? Maybe I need to look in a different direction - I just stumbled upon this information and don't know what Owen Jones was really doing at the time. Moving maybe? Hmmm.... he was a plumber, maybe he was using the Dean Street house as a business? The Jones family lived there for many, many years, at least since the 1830's.
I've recently found out that the original Dean Street houses were demolished and the area was resized and rebuilt in the 1930's. I was crushed to read that.