I agree that there is indeed a marriage theme with Jesus as the bridegroom in John; this involves not just the Cana wedding in ch. 2 but also the explicit identification of Jesus with the bridegroom in 3:28-29, and especially the Samaritan woman story in ch. 4. This text is dependent on OT courtship narratives (cf. 4:3-8, 11-12, 28, 35 = Genesis 24:11, 15-19, 45-46, 62-67; John 4:1-7, 5:18 = Exodus 2:15-17, 21), and the locale and situation is strikingly similar to traditions about Simon Magus and his prostitute wife Helena.
The main point however is that John does not construe this as a literal historical marriage between Jesus and a disciple but in allegorical terms between Christ and his church. The symbolism is patent in the Cana story when 2:4 links Jesus' provision of wine (associated literarily to the miracles of Moses in Exodus) with the Passion (see 18:11), likely through the Eucharist (cf. 6:54-55). The symbolism seems to be pretty clear:
(1) Jesus came down from heaven (his Father's house) to the earth which is where the bride-to-be lives (3:31; 6:51; 14:2). In Jewish betrothal custom, the man must go to the bride's house to propose.
(2) John the Baptist is "the bridegroom's friend" and he introduces the bride-to-be (the disciples) to Jesus (3:28-29).
(3) Jesus offers his bride a covenant replacing the old Law and living water to drink (4:14; 7:37-39; 13:34; 14:15; 14:2; 15:14-17). Jesus drinks of his cup of wine when he dies (cf. 18:11; 19:29-30) and the bride drinks when Jesus is glorified in the resurrection (7:39). This directly parallels the kiddushin custom: the groom-to-be presents his bride with a ketubah (marriage contract) and a cup of wine (over which are said the benedictions). Note that both are symbolized in the Cana story: the old Law represented by the jars of ablution water is replaced by superior wine that Jesus freely dispenses. The synoptics present Jesus as literally giving the cup of wine at the Last Supper while John has this occurring (i.e. dispensing the "living water") after the resurrection (20:22-23). Paul separately developed the notion of Jesus purchasing his Church (like a mohar or dowry) through his death, so that those comprising his bride must remain like virgins free from fornication (1 Corinthians 6:18-20; 2 Corinthians 11:2).
(4) Jesus then returns to his Father and "prepares a place" for his disciples in his "Father's house," when that is done, he "will come again, and receive [his disciples] to myself" (John 14:2-3). This parallels Jewish marriage customs, where the groom leaves his bride for a period of weeks or months and works on preparing the bridal chamber and a place for her move into. Then he returns to her house and takes her home for the wedding ceremony. The Cana story can then be read as an allegory of how Jesus would provide abundant living water (i.e. eternal life) for those joining him in the marriage feast (cf. 145 gallons in John 2:6 -- more than enough for everyone). Revelation 19:7-9 depicts the wedding and marriage feast in heaven between the Lamb and his bride. Although the Cana story prefigures Jesus' provision of living water for the eternity of his beloved disciples in his Father's house (cf. Revelation 21:6), Jesus' response in John 2:4, referring to the hour has "not yet come", points also to his role as the bridegroom offering wine to the bride at the betrothal, in advance of the wedding itself.
