The "Wandering Jew" is a European folk motif that was then applied to the plant. The following is an excerpt from my Introduction to Folklore, which evolved over the years as I taught a course in this subject; see #4, but I provide the rest for context:

Europeans were fascinated by the idea of condemned souls, either of individuals or groups of people, who could not find rest. These unfortunates were forced to exist in a nether world, appearing occasionally before the living as evidence of their hideous or peculiar plight. Such motifs have been favorites with artists and writers. It is possible to identify six types of these beings.

1. The “Wild Hunt” is probably the oldest, occurring in ancient Greek sources and Scandinavian mythology. A cluster of stories refers to ghostly riders who race across the landscape or the night sky, questing for some phantom quarry that they can never catch. Legends tell of people seeing this eerie phenomenon. There are occasional references to the leader as being the god of death.

2. The “Sleeping Army” is a motif that appears in a variety of stories telling of a group of warriors killed in combat, who haunt the battlefield or wait inside a mound for some future conflict. People often believe such an army serves as a matter of last resort, a supernatural force that will awaken if their country is threatened with destruction. King Arthur’s knights are often regarded as sleeping in this way, waiting for the return of their king, healed from his wounds after recuperating in the western island of Avalon.

3. The “Flying Dutchman” is one of the better known and often used motifs of the condemned souls. This motif describes a phantom ship of ghostly sailors who travel the seas but never find harbor or rest. Their only respite comes once every century, when they are allowed to anchor at a legendary port. Their ship is seen in bad weather. The story seems to be of medieval origin.

4. The “Wandering Jew” is also a motif belonging to this class. Like the Flying Dutchman, the Wandering Jew appears to be of medieval origin. The legend tells of Ahasverus, a shoemaker of Jerusalem who refused to allow Jesus to sit while carrying his cross to Calvary. His fate is to wander the world, longing for rest.

5. The Will-’o-the-Wisp is described in Chapter 4. The character was not good enough for heaven and made himself feared by the devil, and so he was exiled from hell. He carries a burning ember, a relic from the time when he briefly entered the abode of Satan, and with this phantom light, he lures nighttime travelers away from their destination. This character is common in Britain.

6. There are also various legends of medieval origin about cities that sank underground or into the sea because of some collective sin committed by the inhabitants. These towns return to earth every hundred years for a few hours, only to sink back to their eternal existence in perpetual limbo.

The legend of Ahasverus, the Wandering Jew, is grounded in anti-Semitism, and must be understood in that context. The name was then applied to the plant because of its long meandering vines. The name was not invented for the plant. I have no way of knowing if the botanists who applied the name were considering the hateful roots of the legend, but botany is at least one step removed from the prejudice evidenced in the legend.