That particular car has absolutely nothing to do with Red Bull or Red Bull Ampol Racing, and as it is an official homologation prototype owned by Supercars, who should not be seen as favouring any particular team or brand, it should absolutely not have been seen running around Bathurst as a rolling Red Bull billboard.
They could've just as easily used the ZB for that purpose, and it's an actual Red Bull Ampol Racing vehicle.
Edit: Whether it be rightly or wrongly, this is exactly the sort of thing that brings Supercars reputation into disrepute and is part of the reason why they get called out on showing favoritism to T8 and Red Bull.
Ps: Don't get me wrong here, I don't think T8 gained anything more than brand exposure here and certainly nothing in the way of an performance or driver advantage over any other team.