The question of which vine is being contrasted when Jesus claims to be the "true vine" (John 15) received this answer that the vine contrasted with the "true" vine is Israel; taken from Egypt, planted in the promised land, grown great under God's faithfulness and yet uprooted and fruitless, cursed on account of their own faithlessness.
Psalm 80 describes Israel as a vine. Brought out of Egypt, and planted like a plant potted and travelled and transplanted in a foreign land. Grown vast, with boughs like cedars. But, latterly, burned with fire, in judgment. Wasted, and forlorn. Fruitless. Carried off to another land, uprooted. A similar figure is the fig tree, which Jesus cursed, which bore no figs at the proper season, that is to say the season of the coming of the Son of man. Thus, cursed. But He, himself, is the true vine. Not a figure of that which is yet to come. Not a figure which, itself, failed even to properly, in faithfulness, represent that which it was supposed to figure. But he, himself, is come, the true vine and the branches which are fixed in him shall be fruitful.
The answer builds upon the notion that those things which are intended to prefigure or foreshadow greater things have fulfilled their purpose once that which is foreshadowed arrives. This is carefully expounded in Hebrews chapters 7-10, summed up for example here:
Thus it was necessary for the copies of the heavenly things to be purified with these rites, but the heavenly things themselves with better sacrifices than these. For Christ has entered, not into holy places made with hands, which are copies of the true things, but into heaven itself, now to appear in the presence of God on our behalf. Nor was it to offer himself repeatedly, as the high priest enters the holy places every year with blood not his own, for then he would have had to suffer repeatedly since the foundation of the world. But as it is, he has appeared once for all at the end of the ages to put away sin by the sacrifice of himself. And just as it is appointed for man to die once, and after that comes judgment, so Christ, having been offered once to bear the sins of many, will appear a second time, not to deal with sin but to save those who are eagerly waiting for him. - Hebrews 9:23-28
What are the implications of this for those who hold that God has separate plans for Israel and for the Church (dispensationalism); who hold the eschatological idea that the Church will be raptured out of the world so that God can once again turn His attention toward Israel during 7 years of tribulation followed by a literal reign, of Christ on earth, from a Jerusalem with a rebuilt temple and a re-instituted sacrificial system?