Was also in Newfoundland earlier this summer, and echo that Bannerman seemed tops.
Our hotel was right across from them, and the Brewdock bar, so that was convenient
I made it out to Port Rexton Brewery, past Trinity on the way to Elliston, and really enjoyed the small-town country vibe there, with live music.
The NLLC (their version of LCBO) had a location not far from there that had a good selection of local craft single cans. Ninepenny, Landwash, Dildo, Baccalieu, Boomstick, Bootleg and Banished all had brews at the NLLC so makes sense visiting the shop.
Most breweries had limited hours on Sunday, the day I had to explore more, so didn't make it beyond the downtown ones (aside from Port Rexton).