Blizzard has just posted some new changes for the Enhancement Shaman Tier Set on the Patch 11.1 PTR.
Greetings Enhancement Shaman. We’ve made changes to your Liberation of Undermine tier set bonuses based on your feedback. In a future PTR build, we’ll be updating your tier set to the following:
2-Set Bonus – Your spells and abilities have a chance to activate a Winning Streak! increasing the damage of your Stormstrike, Lava Lash, and Doom Winds by 5%, up to 25%.