It is, effectively, just another booze. We are already having more diplomacy than we know what to do with. We have other alcohols to stretch our freshwater supplies and the prestige is purely marketing. If things develop differently, beer might be the big rage, so it's not that great for prestige either
Again, it's not really just another booze.
At best we have beer, fruit liquores, and fermented milks. None of these can be added to water, stored long term, or produced in sufficient volume. Distillation isn't a thing yet.
Beer doesn't quite have the same qualities for travel use that wine does unless it is heavily hopped and barreled in a cool spot. It skunks, and actually goes bad. So it isn't really even a good trade good for a year long journey.
Not that beer is bad, it's nutritious, potable, and easy to make. It's also more of a beer porridge than anything else at this point.
As for diplomacy, it goddamn well overflows, so your point about having enough is, well, pointless. It overflows into art, which overflows into mysticism. Art that can be spent on proclaim glories or megaprojects and mysticism that is spent on megaprojects or anything at all science related. Keeping these at max makes us attractive trade prospects, and more importantly, helps us get into golden ages faster.
My whole point here, is that there is a very good reason we were given the option to set up vineyards. It is because it will be useful and play into the gardening aspects of our civ. AN has yet to give us a useless option, and I'm frankly a little baffled that some of you are dismissing it so offhandedly.
Edit:
It's absolutely not.
WINE 101: Wine History
[For centuries wine was produced and enjoyed with little thought for and no true understanding of its underlying science, wine evolved through "spontaneous generation," as far as anyone knew. French chemist Louis Pasteur, among many discoveries relating to his germ theory of diseases, first proposed and proved, in 1857, that wine is made by microscopic organisms, yeasts. This led to the discovery and development of different yeast types and properties and ultimately to better hygiene, less spoilage, and greater efficiency in wine production.]
Wine lead to germ theory.
Big Picture
Viticulture and also important steps in learning how to modern agriculture due to how involved a process it is in plant husbandry. Oenology itself is potentially important to chemistry. Not to mention the innovations and advancements required to properly do these things. I fully expect storage and agriculture to improve due to Vineyards.
more wine and science;
Fermenting knowledge: the history of winemaking, science and yeast research
So yes, I want the vineyards.
They are also the first homegrown progression in our agriculture tech since terra preta.(black soil)
