Acacia floribunda is in the Census as Doubtfully naturalised. Possibly a number of specimens from several sites would remove the doubt. Some of the CNM sightings were originally called A. longifolia which is another introduced wattle.
Did you mean A.rubida? The perils of predictive text. I don't see any bipinnate juvenile foliage often seen on A. rubida but otherwise it is a good fit.
Thanks for comments M&M There were a number of young plants of the same type, ie with the same phyllodes, but none showed the typical A. rubida bipinnate juvenile foliage. I will try to take more & better photographs. There are all kinds of wattles (and grevilleas) planted along Federal Highway so it can be any species ...
Definitely not A. floribundas. Could be anything having escaped from roadside plantings which are numerous along the highway. However, looks like on of the forms of A. rubida. In Grassland Flora, we noted two forms of A. rubida. There is a more common form from lower sites, and a sparser, lower form with bluish leaves from higher, rockier sites.