I think - no evidence to justify this - that you're just smelling the vine. The vine and the leaves of tomatoes smell really strong. I bet if you took one of the vine tomatoes off the vine, washed it, left it for a few hours, you wouldn't be able to smell that smell any more.

I have considered whether the leaves of tomatoes are edible, they do have such a pungent smell. I was told they are poisonous. I could google it, but would that not ruin the fun?