An Elemental Mastery build can work on Yae Miko but it is ultimately a DPS loss. Elemental Mastery will boost her totem damage in addition to offering powerful Elemental Reactions, but her Elemental Burst will lose out on a significant amount of damage that often isn't worth it. I don't recommend going all-in on Elemental Mastery. Only do so if you have a particular type of playstyle in mind.