What Do Lilacs Smell Like?

[Brownlie]

lilacs sweetened the air, -- I would suggest maybe adding more description on the actual smell of lilacs
or rather the canned scent they shove - A phrase like "or rather" may be interrupting the authority of the poem as a mode of communication. That type of phrase may be warranted, in my opinion, if you're trying to capture a type of vernacular voice.
into bottles and pump -- I like the canned lilacs and would maybe accentuate that before mentioning regular lilacs in the first line.
into motel rooms. -- More on the motel rooms. "Motel room"s alone may not communicate as much as it could.
we turned on classic rock -- Maybe mention a particular song or set of songs.
to make us feel defiant -- Maybe show this instead of telling this.
and drank bourbon because it
tastes like sorrow. -- How does bourbon taste like sorrow? It can, perhaps, be a highly detrimental habit or coping mechanism, but how does it actually taste like sorrow?
we danced in the dark,
too drunk to turn on the lights,
or maybe just afraid of what we might see. -- Cliff hangers like these can be good endings, in my opinion.

Made some suggestions. I liked the canned lilacs, interesting idea. Good luck.