Looks like it took long enough just to get across the Bay. There was a letter in the Geelong Advertiser in November 1848 complaining "Yesterday I was a passenger on board of the Aphraisia, from Melbourne to Geelong. We left Melbourne at half-past ten a.m., had a head wind all the way, and did not arrive at Geelong until half-past ten p.m. ...What I complain of is, that this vessel did not carry a boat, in consequence of which neglect on the part of the owners, the captain was compelled to diverge from his course to borrow a boat from one of the vessels at Port Henry."
Normal passage across the Bay from Melbourne to off Queenscliffe is about 2 hours. I have done it a few times in the Oronsay, Orcades, Fairsky, Australis, and the QE2.