The deal, which also includes helping island-based coaches and young players, came about through City's Guernsey-based chairman Steve Lansdown.
Guernsey FC boss Tony Vance has had talks with City manager Lee Johnson about the possibility of bringing in players to his side.
"It will benefit Guernsey football, which I'm excited about," Vance said.
Guernsey FC are just four points off the relegation places in the Isthmian League Division One South and often face problems being able to get enough players together to form a competitive side for away games.
They have gone almost a year since their last away victory.
The club has never used loan players before, with the rules of the team being that players must be based in Guernsey in order to qualify to play for the club.
"It's a realistic thing to do, all the other clubs do it in our league," Vance told BBC Radio Guernsey.
"We're a Guernsey football club, there's no doubt about that, and I've emphasised that so much that I'm looking at the pathway of our players.
"It won't be any way detrimental to our pathway, it will enhance us.
"It's well documented that we struggle away from home with getting players, so they're only a phone call away.
"Somebody from Bristol City might be boosting our numbers, which will be much needed when I've looked at every resource possible in Guernsey."
Guernsey FC could bring in loan players from Bristol City after agreeing a tie-up with the Championship club.