Hmm, not sure about that. Sydney here. I can't think offhand of a context where 'No, yeah' would have much meaning, if any. I never hear it. Does sound like bush talk, maybe, but not sure. e.g. "You don’t like me, do you?" "No, yeah" (or "yeah, no") would just be a meaningless, confusing response. You'd say "Yes! of course I do" or something.
There's that old joke where a lecturer is telling the audience about how two affirmatives never make a negative in English, and a voice is heard "Yeah yeah". I guess you could try "You don't like me, do you?" "No no, I do!". But whatever's said, the meaning would be determined mostly by the tone of voice, facial expression, body language etc
