Thats how it worked for me. I was initially awarded JFK, missed BOS on the first system bid, got it on the 2nd. Grand total from newhire Day 1 til flying trips out of BOS was about 8months. 2 months of that was spent in training/IOE.

System bids come out 4 times per year, with the occasional extra Supplemental bid thrown in somewhere.

Even when I was based in JFK I was getting Long-call reserve a few times per month which is easily doable from the BOS area (14hr callout). Commuting to reserve in JFK wasnt nearly as bad as I expected it to be, but your mileage may vary.