Although it is hard to say whether the six jars represent six specific disciples, there may be reason to consider the jars as representative of humanity in general or the disciples of Christ in particular:
- So they will hang on him all the glory of his father’s house, the offspring and the descendants, all the least of vessels, from bowls to all the jars. (Is 22:24)
As the first of Jesus’ signs, the wedding at Cana is intriguing because of how different it is from all of Jesus’ other miracles. The OP’s question and interpretation prompts me to think about the symbolism in this story. Although not a parable, this story includes many of the prominent symbols of the New Testament. The wedding, the bridegroom, the stone, the jars, the water, the wine, the servants, etc. - each of these elements, whether singly or in combination, seem to point to something beyond itself.
Once I began thinking about the symbolism embedded in this account, the hard part has been how to stop. There seems no end to the connections that can be made. Almost every word seems to recall something from the past or foreshadow things that have yet to come. The OP’s interpretation focuses on the theme of multiplication and the spreading of the Gospel message. For me, what stands out is the symbolism of the water and wine, and the theme of transformation.
The setting is a wedding banquet, where there is “no more wine.” On one level, the wine represents the life of the banquet. Considered at a deeper level, wine, or “the blood of the grapes” (Gen 49:11), represents the life of the spirit; and the absence of wine represents a state of spiritual thirst and sin.
Mary says, “Do whatever he tells you.” She directs the servants to listen to and obey Jesus' words. By extension, her words can be seen as a plea to the servants of God to hear and obey the words of the Gospel. They echo statements from elsewhere in the text:
- “Behold, I am going to send an angel before you to guard you along the way and to bring you into the place which I have prepared. Be attentive to him and obey his voice (Ex 23:20-21)
- While he was still speaking, a bright cloud overshadowed them, and behold, a voice from the cloud said, “This is My beloved Son, with whom I am well pleased; listen to Him!” (Lk 17:5)
Jesus tells the servants to “fill the jars with water.” Considering Mary’s words and how the water is poured and drawn leads me to think that the water represents the words of the Gospel. Consider that the servants of God have been pouring and drawing the words of the Gospel ever since and will continue to do so for generations to come.
Once the jars that are set for purification have been filled to the brim, the water is turned into wine. This miracle symbolizes the transformative and life giving power of the words of the Gospel acting in the soul of those who listen and obey:
- The words that I have spoken to you are spirit, and are life. (Jn 6:63)
- Simon Peter answered Him, “Lord, to whom shall we go? You have words of eternal life. (Jn 6:68)
Furthermore, when we consider that Jesus himself is the Word of God (Jn 1:14), then another level of meaning opens up. The transformation of the water into wine then becomes a foreshadowing of the hour when the wine will become the blood of Christ, the blood of the new covenant that is poured out for the forgiveness of sins:
- And when He had taken a cup and given thanks, He gave it to them, saying, “Drink from it, all of you; for this is My blood of the covenant, which is being poured out for many for forgiveness of sins. (Mt 26:27-28)
As the first of the seven signs recorded by John, the miracle at Cana seems to be a roadmap for Jesus’ ministry, and the overflowing wine, 25-30 gallons times six, serves to fulfill the words of the OT:
- “The days are coming,” declares the LORD,
“when the reaper will be overtaken by the plowman
and the planter by the one treading grapes.
New wine will drip from the mountains
and flow from all the hills, (Amos 9:13)
- He will tether his donkey to a vine,
his colt to the choicest branch;
he will wash his garments in wine,
his robes in the blood of grapes. (Gen 49:11)