Ooh, I'd recommend keeping anything with vinegar far away from your wine stuff in the future... and make sure that syphon gets very well soaked and rinsed before you use it... theoretically all it takes is one single cell of the wrong type of bacteria.
A good long soak in distilled water might encourage whatever volatiles are there to leach out (distilled water has nothing in solution to prevent anything else from dissolving into it), but honestly, with the contact time involved in racking your wine, there should be little to no odour/flavour transfer to your batch of wine. If you want to see what kind of flavour transfer to expect, soak it for half a day in tap water and then taste the water, and understand that that amount of plastic flavour will be divided by contact time and spread over the whole volume.
If it can be taken apart so that all parts are exposed and aired out, that might be another thought, it might just be offgassing...
When I first got my new equipment, it smelled faintly plastic-y but now it all smells like wine from years of wine exposure, maybe a good long soak in some excess must and then sanitize the crap out of it before use?
I once had a plastic travel mug I used for my morning tea and my husband once used it for an herbal tea involving garlic, and I had to soak it overnight in bleachy water twice to get the garlic scent out and I had to soak it for a week in strong tea (changed several times) so the residual bleach would stop bleaching the flavour out of my Tetley!
