Freeway is correct. Virgin Share the Delta Crown Room lounge ( beside gate 70 I think airside- In the terminal that VS uses so it is reasonably close ot the 80's gates that VS uses.
The shared lounge is the Delta one as pointed out earlier, it is on the second level of the atrium of the departure annex. Where the atrium is next to the transit trains, the one with Starbucks to the left, the lounge goes all the way around overlookign the main level below
You can also get in their with a Priority Pass if you're not flying UC or VS Fc Au.