Green’s Dictionary of Slang

(Aus.) Victoria Bitter brand beer.

2002		Google Groups:rec.sport.cricket 8 Jan. 🌐 The letters VB stands for Victoria Bitter, which is a brand of beer in the stable of the Fosters Group Limited. [...] [reply] Or Vomit Bomb.
2004		Google Groups: alt.pro-wrestling.wwf 4 Aug. 🌐 VB is called Vomit Bombs. [reply] That’s due to the effects of drinking a few too many of them, nothing to do with the taste. What it tastes like is sheepshit soaked in meths.
2006		Urban Dict. 6 June 🌐 Vomit Bomb: A colourful description of Victoria Bitter VB, a popular and iconic Australian beer. The term is obtained using the first two letters of ‘Victoria Bitter’, and is generally used as a reference to the cheap cost and powerful intoxicating effects of the beverage. ‘Hey Barry ‘ya tosser! Throw me a Vomit Bomb!’ .
2016		Dave’s Beers of the World 11 July 🌐 Regardless, it is an Australian icon whether we like it or not and I recommend you try a Vomit Bomb at least once in your life.