Interesting. I thought they banned it like the MBTA (or atleast I think the MBTA did). When I first moved here, It was extremely odd to see stations selling 24oz cans, people with bottles of wine and yesterday, 2 cases of pint beers (18 total). I've always wondered if the people that drink on Metra go home drunk....
In constrast, the CTA prohibits alcohol for obvious reasons.