So, the full sentence in the Guide is
"Like at least 25, after the sickness event. Scene in tavern happens from 20:00 and it can't be after using love potion that day."
If you've already completed the scene, you can't do it again, and I don't know if a heart appears for this scene. I think the other two either appear directly after the Hot Springs scene, or sometime during the Full Moon event. But I could be wrong.
Ok, just rechecked, and I can confirm that the Bar scene does not give you a Heart, but the cottage can, and the Hot Springs scene can.