Wine investment companies...it's just one of those areas. Like coloured diamonds, land banking, carbon trading, penny stocks etc etc. How long has the site been down?
It's good that you asked, but you should probably be a bit worried that you needed to in the first place.
Anyway, if you disagree, take the job and find out for yourself.
Do you know that someone was already asking about them on this site? Got no answers but reached his own conclusions.