I've seen both these terms in halachic sources, in reference to a B'racha that should not have been made. But I'm not sure what the difference is.
They are related but they are not the same. The way I recall this being explained to me in a halacha shiur is from the example given for a b'racha she'eina tzaricha being making a bracha or brachos on food when ultimately one is going to wash soon afterwards. These brachos would not be l'vatala because one needs to make a bracha before eating but they would be she'eina tzaricha because if that person would have washed first then they wouldn't have made those brachos.
A bracha l'vatala on the other hand is a bracha that should not be made at all. For example making the bracha al netilas yedoyim when washing was a chumra and not an obligation or repeating a bracha that was already said within the timeframe the original bracha still applies.