I admit that I was a bit lost in the details of plot, with all the weird sounding names and hyphenated pronouns. However, the luscious imagery carried the story for me. I'm more of a beer & steak kind of a guy, but I readily identified with the language used and at times could almost taste the wines as they were being described.
My views on the various incongruities are similar to ElectricPaladin's. I think the point about the narrator being a very biased POV was very important, and possibly missed. A historical parallel might be the Opium Wars that the British fought with the Chinese in the 1800's. To the Chinese, this was a watermark point in history, both an extremely humiliating insult on their national pride and what would ingrain a very strong sense of anti-western/anti-colonialism that would affect modern Chinese foreign policy over 200 years later. To the British, however, this was not much more than one of many "police actions" (to borrow an modern phrase) to keep the colonies in check, and may not have warranted much more than few newspaper headlines. So in that sense, when Earth was said to "declare war" over a wine, it might have only been the equivalent of a minor conflict to the citizens of Earth. From the story, the "war" with Earth certainly seemed to be one-sided enough.
Furthermore, I think some of the incredulity about starting a war over wine comes from our unique modern perspective, where we can surely stop by the corner mart and buy a couple bottles should wish. Let's not forget that at one point in time, quite a few wars (or let's say conflicts) were fought over Spices, many of which are also cheap and easily available now. At a point where a few rare spices (like nutmeg, mace, cloves) were only found on a small chain of Indonesian Islands, it was said that a single sailor could bring back one sack of spices on such a trip and be able to live in relative affluence for the rest of his life. Now, imagine such economic forces on an inter-stellar scale.
Personally, I imagine the technology level of this story (where inter-stellar travel seems to be relatively easy) as basically Star-Trek-like. They could very well have the ability to synthesize or easily transport basic food-like products very cheaply. Imagine a McDonald's like "food printer" that had a basic nutritional "food-goo" feed along with an array of flavor and color toner cartridges, which would allow you to easily fabricate anything along the lines of a quarter-pounder, or a california roll, or even a ham & turkey gyro. We basically have the tech to do that right now. All the Golubash colonists would have to do was to obtain a steady energy supply, a source of water for hydroponics, and an occassional earth-delivery of stuff that wasn't easily fabricated. In an environment like that, I think the commodities for interstellar trade would be anything that was relatively hard to fabricate and easy to transport, e.g. wines, coffee, tobacco, rare metals, cultural items. I could easily see the Wine trade being the subject of dispute between various cartels, governing bodies, and small sentient planets.