I cannot see the Sands McDougall references you make.
What district or suburb is the Williams Street address?
listing ones name in the directory was by application. It was not automatic and there was a cost involved.
Judith above has clarified the Abbotsford Street was Robert John ROBEY
John Robert ROBEY was in Melbourne in 1896 and wealthy enough to own a gold watch and chain
https://trove.nla.gov.au/newspaper/article/193978722 In 1898 objection to his to voting at Hotham as Robert John ROBEY
https://trove.nla.gov.au/newspaper/article/9790666 BUT
In 1899 John R. ROBEY voted in the Federal Referendum. Tobacconist of 82 Hotham street Collingwood.
Seems to be a lot of swapping around of given names

Looking at Robert ROBEY in England from 1901
Who was the father of the girl named Mary E aged 6 years who is with Robert and Charlotte in the 1901 census?
He describes her as his niece. Was she? To be that she would seem to belong to William and Charlotte Ellen, but William seems to have died well before her birth.
Who were her parents?
Sue