There are three records of Jesus saying things like this, all from when he shared the last supper with his disciples:
“I will not drink again of the fruit of the vine until that day when I drink it new in the Kingdom of God” (Mark 14:25)
“I have earnestly desired to eat this Passover with you before I suffer. For I tell you I will not eat it until it is fulfilled in the Kingdom of God… from now on I will not drink of the fruit of the vine until the Kingdom of God comes.” (Luke 22:15-16,18)
“I will not drink again of this fruit of the vine until that day when I drink it new with you in my Father’s Kingdom” (Matthew 26:29)
The funny thing is that Jesus did drink the fruit of the vine again, the very next day, in the sour wine (vinegar) on the cross (John 19:29-30). So is there something particular about the ‘fruit of the vine’ at the last supper that he would not have again until the Kingdom? The answer is, obviously, yes — it was the special memorial that he commanded believers to keep from that time forward (1 Corinthians 11:24-26). That was the particular meal and fruit of the vine that he wouldn’t have again until the Kingdom. The Greek text is explicit that Jesus was referring to ‘this fruit of the vine’ and ‘this Passover’ (Matthew 26:29; Luke 22:15-16). So that’s why the sour wine on the cross doesn’t ‘count’. There is reference to Christ eating with his disciples after his resurrection (Acts 10:41), but not to him sharing with them the memorial bread and wine.
Sharing a meal is in many cultures a special sign of fellowship or friendship. On the night of the last supper, Jesus spoke of the ‘cup’ to refer to his death (Matthew 26:27-28,38-39,42), but of the ‘fruit of the vine‘ to refer to the faith of his disciples (John 15:1-8,16). So it’s a special fellowship meal, not just the taste of wine, that Jesus is looking forward to in the Kingdom: ‘ “I will not drink again of this fruit of the vine until that day when I drink it new with you in my Father’s Kingdom” ‘ (Matthew 26:29). Several passages describe a fellowship meal being shared in the Kingdom (Psalm 22:25-29; 116:13-14; Isaiah 25:6; Luke 12:36-37; 13:29; 14:13-15; 22:30; Revelation 19:9).
My work group holds special lunches every month or so where we share ideas. If the organiser says, ‘We won’t have any more lunches till next year’, he doesn’t mean none of us will ever eat lunch until next year, just that our next special work lunch will be next year. Jesus Christ has been looking forward not just a few months, but centuries on end, to sharing again in person the special fellowship meal with his disciples!