Ask Dionysos...
And Philo, On Dreams, II, 249:
And who can pour over the happy soul which proffers its own reason as the most sacred cup, the holy goblets of true joy, except the cup-bearer of God, the master of the feast, the word? not differing from the draught itself, but being itself in an unmixed state, the pure delight and sweetness, and pouring forth, and joy, and ambrosial medicine of pleasure and happiness; if we too may, for a moment, employ the language of the poets.
It is the first sign (sèmeion) in the Gospel of John only, that should tell enough about the symbolical intent.
It is interesting that "wedding" and "new wine" are linked together in the synoptic sayings too, from Mark 2:18ff on:
Now John's disciples and the Pharisees were fasting; and people came and said to him, "Why do John's disciples and the disciples of the Pharisees fast, but your disciples do not fast?" Jesus said to them, "The wedding guests cannot fast while the bridegroom is with them, can they? As long as they have the bridegroom with them, they cannot fast. The days will come when the bridegroom is taken away from them, and then they will fast on that day.
"No one sews a piece of unshrunk cloth on an old cloak; otherwise, the patch pulls away from it, the new from the old, and a worse tear is made. And no one puts new wine into old wineskins; otherwise, the wine will burst the skins, and the wine is lost, and so are the skins; but one puts new wine into fresh wineskins."
To which Luke (5:39) adds something which is reminiscent of the Cana story:
And no one after drinking old wine desires new wine, but says, 'The old is good.'
It might be another case of one wisdom symbol expressed in two forms, (1) parable and (2) miracle story.