If it does, it rarely if ever appears to be publicised.
This may indicate (a) celebrities only travel on QFd/ QGFi - unlikely
(b) QFd staff can be aggressive and confrontational, or passive aggressive, instead of polite - possible
(c) the media only considers incidents on QFd/QFi newsworthy so these ones get blown up - possible.
"If it does, it rarely if ever appears to be publicised" : You mean publicised in the Australian media? In a small country with only one real airline, this is perhaps to be expected. What do you think the reader-interest would be here if the story was about a Bolivian band flying Fenca Air? Of course it would be zero.
As far as your alternatives, let me see....
(a) I think that within Australia celebrities choose Qantas always as first choice. Because it is Australia's only real airline. And any decent celebrity has "minders" - professionals who try to keep the little darling stars out of too much trouble. In a country with only one real airline, and a small backup, it is obvious that any decent minder would send their fickle charges on QF first. Because if they misbehave there is always the option of quietly moving them on Virgin, where they know they will keep their heads down in shame. If they sent them on VA first, they know that any incident will prevent them from flying the real airline too.
(b) I love this scenario you put forward - and again it reaffirms my point about Qantas being our only real airline. YES! EXACTLY! Qantas staff have the proverbial "balls" to use these specific tools to deal with the "W from WP"s. Good on them! As a non-celebrity, I live for the day I am on a plane where there are celebrity idiots aboard when the QF staff get very aggressive and confrontational with them. I am certain that all the other pax want exactly this!
(c) as per the start, australian media is obviously QF focussed - they know in advance that exactly the same story about anything aviation will get 10 times as much interest if it relates to QF rather than the sideshow of VA. These days VA has to pull off something absolutely spectacular to get noticed. A minor crack in a QF airframe is equivalent to an uncontained engine explosion on VA. That is just how it is....