Are you looking for a freebie or a decent restaurant for wine and cheese? For the freebies, check portlandfoodmap.com As for restaurants, my best choices for wine and cheese plate are Vignola, Fore St, Caiola's, NOSH, Novare Res (Beer though, not wine).
58 Pine St, Portland, ME 04102
10 Dana Street, Portland, ME 04101
Correction: Novare Res does indeed have wine available although far from high end glass pours. It's a shame, come to think if it. They are so particular about their draught and bottle beer selections that they should pay attention to the wines as well. The wines looked as though mostly available in the supermarket
Are you looking to host a private event? The Cheese Iron in Scarborough should be able to accomodate you.
You could also check out Rabelais bookstore for upcoming events there.
There is also The Wine Bar on Wharf St...comfortable to hang out and drink by the glass. Serving appetizers, etc.