Anderson, who made 54 appearances for the Pirates between 2004 and 2006, becomes the second ex-player this summer to agree to help the club track up and coming young talent following in the footsteps of former Rovers striker Giuliano Grazioli.
"John obviously sees a lot of the teams in the Unibond League, which includes sides like Bradford Park Avenue and FC United of Manchester," said Rovers' chief scout Paul Molesworth.
"He says he has seen some good players at that level and a couple of them have gone on to sign for Football League clubs.
He has agreed to keep his eye out for people who might be able to do a job for us and let us know about them.
"I was the one who brought John to Bristol Rovers during Ian Atkins' spell (as manager) here and he has since gone on to get his UEFA B coaching licence. He will be another useful addition to our scouting network."