This is a potential settlement but you have to meet these requirements:
• Complete the miscellaneous quests given by Joe Savoldi, Deb, and Mayor Kessler
• Complete the Institution quest “Battle of Bunker Hill”.
Meg will offer you a “tour” of the hill for 10 caps. It’s not really a tour so don’t bother. A “Join the Railroad” holotape is found on the counter. There’s an issue of Live & Love on the topmost part of the monument.
If you asked Deb for a job, she’ll ask you to clear the National Guard Training Yard. This location is tied to many other quests so chances are you have already cleared it. You can haggle for more caps and if you already cleared the place, you’ll instantly receive your reward. Deb will advise you to talk to the mayor as well. She also sells some unique armor pieces and a unique weapon.
If you talk to Joe Savoldi in the only bar of town and asked for a job, he’ll give you a misc quest to find any trace of Brent Savoldi. You can find the remains of Grandpa Savoldi inside the Old Gullet Sinkhole.
If you talk to Mayor Kessler, she’ll ask you to deal with the raider group Lead by Zeller and rescue the captured caravan workers. They’re located in East Boston Preparatory School to the east. If you cleared this objective, you'll be able to craft Trade Caravan Posts in your settlements, allowing caravans from Bunker Hill to visit your settlement, no matter where it is (even if its in the remote Spectacle Island)