@zleap
Its a complex question that has less to do with how far smell travels and more to do with the sensativity of the nose and chemical "noise"
So first off, no, aromatic compounds, despite the name, are not (always) compounds that are smelly. Its just a very poorly named property that means a compound has what we call an "aromatic ring" which is a 6 carbon ring witb alternating single and double bonds. They have nothing to do with smell.
So back to the question, smell effectively travels infinitely far given enough time, assu.ing we coubt even a single atom as suffecient. So in reality how far a smell travels has more to do with the sensativity of the nose and the diffusion rate of the compound.
Take humans and the geosim compound as an example (the smell of wet dirt after a rain). Humans are extraordinarily sensative to this compound. Just 5 atoms in a trillion is enough for us to detect it. For comparison mercaptan, the smell of grapefruit, is 1600 atoms per trillion threshold.
Now distance would depend on wind, time, and temperture effecting diffusion. Its complex but on a windy day a few atoms can make quite a distance im sure.
As to some real world numbers, bears can smell most cood at approximately a 20 mile distance.
@oldrawgabbit @krypt3ia