Stehen, liegen, and sitzen are the verbs used with position. They don't have exact English equivalents (stand, lay, and sit are not used exactly the same).
It means that wine is upright on the bottom. The could be the bottom shelf or bottom floor or bottom of the truck. That part is left unstated, probably because it is implied in whatever context this sentence would be used.
The English is not only odd, it makes no sense. This is one of those cases where DL should NOT give the literal translation. Rather, as mentioned in other posts about idioms, it should give a natural English sense, with an explanation as to the literal meaning to help understand the idiom. But giving only the literal, nonsensical translation does not help us learn how to use the German phrase.
But isn't the whole point of effective translation to make the sentence sound as comfortable and "right" as possible to the ear of a speaker of the language into which you're translating the sentence without violating the sense of the original? "Es geht mir gut" as "It goes well to me" might sound right as rain to a native German. But it's a terrible translation for a non-German.
I took it to mean (and was marked correct for): "The wine is underneath"
The first vision that came to mind was somebody looking in a cabinet for a bottle of wine and being told that the wine is underneath where they are looking; would "der Wein steht unten" be used in that case?