I think the discourse about the vine, branches, and the vine dresser is about God the Father, the Lord Jesus Christ, and the Holy Spirit who indwells the faithful. Since Jesus speaks of the branches using plural pronouns it's clear he didn't mean individuals. "You are the branches" would more accurately me translated (in modern English) as "All of you are the branches" The passage reads this way:
"I am the true vine, and my Father is the vine-dresser. Every branch in me that does not bear fruit, he will take away. And each one that does bear fruit, he will cleanse, so that it may bring forth more fruit. You-all are clean now, because of the word that I have spoken to you-all. Abide in me, and I in you-all. Just as the branch is not able to bear fruit of itself, unless it abides in the vine, so also are you-all unable, unless you-all abide in me. I am the vine; you-all are the branches. Whoever abides in me, and I in him, bears much fruit. For without me, you-all are able to do nothing. If anyone does not abide in me, he will be cast away, like a branch, and he will wither, and they will gather him and cast him into the fire, and he burns. If you-all abide in me, and my words abide in you-all, then you-all may ask for whatever you-all will, and it shall be done for you-all. In this, my Father is glorified: that you-all should bring forth very much fruit and become my disciples. As the Father has loved me, so I have loved you-all. Abide in my love. If you keep my precepts, you-all shall abide in my love, just as I also have kept my Father"s precepts and I abide in his love. These things I have spoken to you-all, so that my joy may be in you-all, and your-all joy may be fulfilled. This is my precept: that you-all love one another, just as I have loved you-all. No one has a greater love than this: that he lay down his life for his friends. You-all are my friends, if you-all do what I instruct you-all. I will no longer call you-all servants, for the servant does not know what his Lord is doing. But I have called you-all friends, because everything whatsoever that I have heard from my Father, I have made known to you-all. You-all have not chosen me, but I have chosen you-all. And I have appointed you-all, so that you-all may go forth and bear fruit, and so that your-all fruit may last. Then whatever you-all have asked of the Father in my name, he shall give to you-all. This I command you-all: that you-all love one another. John 15:1-17
You-all and your-all are my attempt to show where the Greek pronouns are plural.