You have to be careful because the meaning of the phrase "appear in public" can be disputed. I don't believe it would apply to either of the two situations you mentioned. Some people may be put off by a request to sign a release, but if you just verbally ask their permission and record it on your video, that should go a long ways toward protecting you. Don't forget to get location rights from the bar owner, etc.
The focus of your video and even the exact utterance your narrator is giving can also have an effect as was the case when a major network got sued for showing the face of a pedestrian while saying that the area was frequented by prostitutes. The lady pedestrian sued and won, and rightly so.