Run by Sam Treadway, one of Boston’s brightest bartenders, this pocket bar off an alley behind Journeyman (the progressive Somerville restaurant) covers a lot of ground for a companion piece. Though the seasonal menu is full of newfangled inventions (olive-oil washed spirits, smoked ice, foie gras cognac), there is an equally balanced spread of classics, including a Milk Punch that changes depending on Treadway’s mood, or the season.