Did you take OG/FG reading? If so, did the beer fully ferment?
If it fermented fine, I don't think you should worry about yeast. I bet your inconsistent carbonation on the other batch was a result of an uneven mix of your priming sugar. I stir the beer in the bottling bucket after at least every 12 pack I bottle (since my 2nd batch). First batch was inconsistent, but the subsequent ones have been fine.