The home side ran in seven tries for their biggest ever victory over the Wallabies, who have been depleted by injury and player absences for personal reasons.
Rennie will have learnt a lot from seeing his next best in action, but with the future of regular skipper Michael Hooper uncertain after he pulled out of the tour saying he was not in the right frame of mind to play, there will be concern a year out from the Rugby World Cup in France.
"Massive disappointment. Not good enough," Rennie told reporters.
