From experience, it usually takes me 15-20 minutes from landing at 2G to reaching the departure gate at 2F. The shuttle is often immediately available, or at worst shows up after a 2-3 minutes wait. I don't remember much from 2F to 2G, but I think it was even less than that.
As Goldorak said, probably not enough time to enjoy the lounge, still enough time to connect. If you are in Business, you surely don't need to eat at the lounge anyway. Enjoy your meal!