The Son of man is the awakened higher self living fully in the body, taking food and drink, moving among the lowest faculties without recoil, and the crowd's mockery is the lower mind's failure to read a spiritual state through fleshly eyes. Eating and drinking, befriending publicans and sinners, is the higher self entering every level of the person, even the base appetites, to redeem them from inside rather than fleeing them. Wisdom justified of her children means the inner knowing is proven true by what it produces within a person, not by outward reputation.
When the higher self engages the whole of a person's nature instead of holding aloof, the fruit of that engagement vindicates it, however the surface mind may judge.
The Son of man: the awakened higher self dwelling fully in the body, moving through every level of the person
Publicans and sinners: the lower and baser faculties of a person, the appetites the higher self enters to redeem
Wine: the flowing spirit and vital current drunk within, mistaken by the lower mind for mere excess