The Norwich loan star marked his first start in eight matches with a late equaliser to prevent a Chris Eagles strike landing all three points for the visiting Wanderers.
Grayson said of Vaughan afterwards: "We are delighted to have him back in the team. We have seen previously what he can do for us and the quality he has.
"If you paid money to come and watch this game I don't think you were short changed. The game swung backwards and forwards and I have kicked every ball and gone through every emotion. We made some mistakes but we could have nicked it at the end.
"Bolton are a top, top team at the wrong end of the division. They have Premier League experience and we showed we can compete."
On goalkeeper Alex Smithies, who made several impressive saves to deny Bolton, Grayson added: "Alex is a fantastic goalkeeper and he made a mistake last week but he showed his quality.
"He's mentally strong and goalkeepers need that. They can be heroes one minute and villains the next."