West Ham fan Lee professed his admiration for Bonzo when he signed from Leeds United recently, and the feeling, says the former Hammers boss, is most definitely mutual.
"Lee is a good player and I don't think we have seen the best of him yet," says Billy. "He is not the player yet we know he was at Leeds, whether it is fitness or he is finding his way, but it is very early days in his career.
"Hopefully we stay up, Lee Bowyer stays with the club, and he gets even better - because he is certainly a very good player and it will be a big bonus to West Ham.
"He is the right age and with the likes of Carrick, Defoe, Cole, there is the nucleus of a good squad there - there are some good young kids to build around."
Billy, not unnaturally, would hate to see an exodus of players from the club if the worst was to happen - but knows that such an eventuality is inevitable.
"It is not just about Lee. If the club go down then it is going to be difficult for them to hang on to all the good young players," he says.
"That is why it is so important the club stays in the Premiership.
"When I was manager there wasn't the money there was then. Nowadays if you go down it can cost millions and millions of pounds, and it is not so easy to bounce back up because you can lose your good players.
"Looking at Leicester they are doing ever so well but the first division is full of teams that haven't been able to do that like Norwich and Sheffield United - and look what has happened to Derby.
"It can have a devastating effect. 10 years ago we kept our players and bounced straight back - but it doesn't always happen."