Yes you can use the Williamstown tides... essentially because of the very narrow mouth to Port Phillip the tide ebbs from 3 hours before LW PPH ( ie low tide outside) to 3 hours after.
No probs sailing over the top of Lonsdale Rock ( 6.1 metres on the Chart)... but just stay west of the western limit of the main channel... the bits the big ships use.
Its 10 years since I was last doing this but I think it is the low light that has a white sector that brings you inside Lonsdale Rock... most yachtspeoples aren't game
enough to go that far west... it shows white over the main entrance... red over Lonsdale Rock and a 2* sector inside ..ie west ..of the rock... the pilot boats use it in v heavy weather
With a strong ebb you can actually see and hear the ebb when you are in relatively quiet water
One thing you do need is the paper chart of the entrance.. don't try it with electronic stuff... not enough info.
Also if coming up from the SE ... stay about 3 miles off depending on traffic before coming onto your leading line.. that way you are clear of the tide and aren't going to upset inbound ships.
to show what I am talking about attached.
That crib sheet isn't from Cruising Helmsman about 1990 is it?