Question: Acidic drink interacting with the plastic bottle.

Would you expect any chemical interaction, BTW, when apple-cider vinegar sits inside the plastic bottle they sell it in (versus glass) -- could acid leach anything from the plastic bottle?

If it is ldpe, or hdpe, then the worst case scenario would be ethylene, which either would evaporate, as it does from apples, or oxidize into ethanol. Which would be quickly worked into to the AcetylCoA, one of the main sprockets of the Krebs cycle. But the polymer is very durable, and it takes sunlight UV and high heat to break it.

if polypropylene, then it would be a propylene, eventually evaporating, or becoming isopropyl alcohol (rubbing alcohol), or acetone, which would evaporate, or remain within the body's native acetone content.

the cola bottle material, PETE, is very durable, and is highly resistant to chemicals, especially weak food acids. Acetic acid in vinegar is nothing compared to concentrated main acids.

To summarize, whatever monomer leaching into food would be somewhat below the biologically relevant concentration.