He said a friend of his was involved with development work at Penrith and managed to get four Pikiao players a trial.
"It was a closed trial and it is usually very hard to get into because there is so much talent in that area [in Western Sydney], there is 50-odd clubs in that area," he said.
Following the initial trial in October, Lorne Green and Te Rangi were asked to come back. Te Rangi continued to impress during the following trial period, and was named in one of the final squads at the weekend.
The Penrith Panthers have two teams in the prestigious SG Ball competition - their top side who play under the Penrith Panthers name and their development side who play under the name Western Sydney.
Perham will feature in the Panthers 25-man squad while Te Rangi has made the Western Sydney 25-man squad. Both teams play in the same competition.
Bartle said Te Rangi could play centre or second row and was very humble.
"He is a really good defensive player but I would say one of the best attributes he has is he's just one of those kids that is humble. And if you are new to the team he welcomes you in and doesn't rubbish anyone.
"I couldn't think of anyone else I would want to have that opportunity."
He said Te Rangi had also done well to come back from a knee injury early last season.
Bartle said he would love to take more players from Rotorua over to Penrith in years to come, to trial for the club, and it was a great pathway for top young players.