The Arsenal midfielder has been in red-hot form for the Gunners as of late, hitting 13 goals in all competitions so far, with manager Arsene Wenger tipping the youngster for the Player of the Year gong.
Bale scored 26 goals for Tottenham Hotspur last season en route to sealing a world-record £86m move to Real Madrid, and Coleman, who manages both at international level, believes that there is little to choose between the talented duo.
"When you see what he is doing at the minute, then why would you not say he is at a similar level [to Bale]?," he told reporters. "What he's doing at the minute is enjoying his football.
"He's found his confidence again. He's always had the ability, he just needed to get the confidence back and he's got that.
"You can't be doing what he is doing without that. And he's doing it in every game. If he's not scoring, he looks like scoring. He's involved in everything. Rambo looks brilliant at the minute."
The former Cardiff City starlet is expected to face Everton when the Toffees travel to the Emirates Stadium in the Premier League this afternoon.
Bale has enjoyed a fruitful start to life in the Spanish capital, hitting nine goals in as many appearances in all competitions so far this term.