Wine has long been valued for its medicinal benefits - it figures in almost all the remedies recorded by Hippocrates, from a general antiseptic to cooling fevers. The grape has been part of the triumvirate of good throughout the middle ages, and the triumvirate is those benevolent institutions: the church, hospitals, and vineyards.
The church, some of them at least, had a tradition of helping the poor, and hospitals are one way of helping, which is why many of the first hospitals were in fact started by Monasteries. Most of them also had the tradition of making life comfortable for their members, and wine, in addition to its medicinal uses, was both enjoyable and profitable. This symbiotic relationship was well established by the time of the Barefooted Monastery near Zurich. First documented in 1247, the monastery was renamed "Holy Spirit Hospital" in 1293.
Wine's medicinal and financial properties were also the reason secular hospitals maintained extensive wine cellars. Again, this was true later in the century when the house of "Zähringer" founded the "Hospital of the poor," in the Zurich region.