To simply answer your question, based on your example, of vinegar to wine nothing would happen should it be used on a human. spells are very specific in nature. the way the wording is, the stressing of the syllables, as well as hand movement all can effect the spell. those are facts. so its easy to assume that if magic is that precise and finicky that the objects may also play a part.
we have group spells, specific spells, and vague spells.
a group spell example would be such as a the hover charm,(alot of charms actually) summoning charm, it appears to allow any object be summoned to you, it also may allow you to summon a human ( reference to the yule ball in hp4 where harry thinks he sees to guys summon 2 guys over to them) this is speculative though as weve seen instances when summing a person to you might be ideal, but wasn't used.
Next we see specific spells, lumos (light from your wand), Alohomora (unlocks doors), now these spells are seen only used in specific ways. however could alohomora be used to unbutton that hot girls shirt across the room? i would say no, as A. it would be far to cool, B. its a specific spell made for unlocking doors/locks. I would say based on examples in the books that some transfiguration spells fall into this category, especially a vinegar to wine spell.
finally we have vague spells (dont have the spell names handy but) the spell used to destroy or blast a hole (used in the maze to get through a wall in hp4) can this be used on a human to blast a hole through them? we have the spells to enlarge or shrink i think we have seen examples of hands ears noses being changed with this spell(tho not implicitly stated that these spells were used) can these be used macro'ly on a human to enlarge the entire human, or shrink yourself tiny, it can be used this way on animals but on humans?
i think the rest of the transfiguration spells fall into these, such as turning a human into a ferret, is it a specific human transfiguration spell, or is it the same spell to turn a weasel into a ferret? spells arnt given in the book, and theirs no clues to alot of these spells.