I am a restaurant owner in DC and I have never been to V-no. But it seems to me that the test should be what are the wines offered, what are they charging, and is this lower or higher than the going rate. In most jurisdictions, the question of a space being a wine shop or a restaurant is a legal/license one. If they are a wine shop then they must price their wines for take away. So adding a small corkage may be a great deal. And the cost of opening a bottle and lettting a customer drink it out of glass is not zero. My wineglasses cost about $3 per and for the reserve wine, about $7. They break just from usuage. A small business needs to make up its costs somehow, and charging just the folk who drink in for that part of the cost of business just matches costs to the source of those costs.
Given how most restaurants treat their customers when it comes to wine pricing, places that have lower markups and make interesting wines affordable need support. There are restaurants in downtown DC for example, sell widely available wines by the glass for 5 times their wholesale in many cases. I have experienced the same in Baltimore.
Of course, if their "retail" prices are high to begin with, there is no bargain involved. But the only way to judge is to go there, since they seem to have no website (or at least, Googling for a minute or two did not show one). It would be great for V-no to either get their wines and prices on a website so we can tell, or for someone who is in the wine business or is a wine hobbyist to go there and report back in general terms on what they are offering and for how much.