Vunipola liked Folau's post, stating that "there comes a point where you insult what I grew up believing in that you just say enough is enough".
The Wallabies coach says Folau's comments are too damaging to team culture to warrant another selection.
Rugby Australia has indicated it will terminate Folau's contract unless he can cite "compelling mitigating circumstances" for his latest social media post in which he said hell awaits "drunks, homosexuals, adulterers, liars, fornicators, thieves, atheists, idolaters".
'All professional rugby players in Australia are bound by the code of conduct, and there is a process in place for any disciplinary matter.
While Rugby Australia will sack Folau, 30, for his second anti-gay outburst in a year, and said on Monday he had 48 hours to accept that verdict or face a code-of-conduct hearing, Vunipola has now explained his own views but stopped short of apologising to the LGBT community.
"It was made clear to Israel in writing and verbally when I met with him past year that any social media posts or commentary that in any way were disrespectful to people due to their sexuality would result in disciplinary action".
On April 11, Rugby Australia declared that it was aware of social media posts by Folau.
"He accepted that conversation, he said that he understood that conversation, he shook my hand at the end of that and said he was very clear, and yet he has gone off and done this".
"Getting out in that disrespectful manner publicly is not what our team's about", Cheika said.
When you play in the gold (Wallabies) jersey, we're representing everyone in Australia.
Israel Folau, wearing tape on his wrist adorned with a cross, runs toward the try line to score against England during their rugby union test match in Sydney.
"That's one of the things that's got to be taken into consideration", Castle said.
Vunipola has also been summoned to talks with the Rugby Football Union but the governing body is refusing to provide any details for its meeting, insisting it remains a private matter.
"It's hard being here".
Gibson expressed disappointment that the issue of Folau's religious views had arisen again. We don't pick and choose.
"Absolutely", Folau said. "First and foremost, I live for God now. If that's not to continue on playing, so be it", he said.
'In saying that, obviously I love playing footy and if it goes down that path I'll definitely miss it.
'I have faith. My Christian faith has sustained me through the ups and many downs of my life. One speaker praised Folau for his "boldness" for adhering to God's word.
"I think as it stands right now... you wouldn't be able", Cheika said. But at the end of the day it's not for me or anyone else to condemn a person, we don't know what goes in their life and what has bought them to where they are. I can see the other side of the coin where people's reactions are the total opposite to how I'm sharing it. Folau has indicated he plans to fight to save his career.
"Everybody has the right - and we respect that right - to believe whatever they like. I don't think he's done himself and I don't think he's done our Christian faith any great service by saying what he's said and putting it the way he did", she said in an exclusive interview with the Herald.