My guess is that Jeremy was on the vervain (because dude, the second you realize you've gone off it, you're gonna get right back on as quick as possible. I don't believe he went and confronted Tyler without having a nice swallow of vervain and probably stuffing bits of it into every orifice) and was not actually compelled. I'm betting he's gonna show up several episodes from now in a Big Damn Heroes moment. And there's a part of me hoping he'll have been conspiring with Stefan, because they will now have a "little brothers of older siblings that tend to screw them over for whatever reason" bond".