'Bennelong' is a term used to describe people who wander off when they are drunk only to be seen later on in the evening at their house, having wandered round in a drunken stupor during the intervening time. They are so named because Aboriginal Australians, who have no cultural concept of time, will go on walkabout. One of the most famous Aboriginal Australians was Bennelong whom Governor Phillip befriended in 1789, after whom Bennelong Point, now the site of the Sydney Opera House, is named. This resulted in his name being used to describe this drunken practice.
-"Where's Barry gone to now?"
-"Oh I expect he's gone Bennelong. I'm sure he will make it home safely."