The three days after Christmas celebrate three saints or group of saints. The first, celebrated on the 26th, is the feast of St. Stephen, the Protomartyr. Then, today, the Feast of St. John the Divine, and tomorrow, the Feast of the Holy Innocents of Bethlehem. I suppose that we could lump in St. Thomas Becket, Archbishop of Canterbury, whose feast is the 29th.
Comites Xsti or Christi, if you don't want to use the ancient abbreviation, is the name for these saints: the Companions of Christ. They were given this name in the middle ages since their feasts came right after the Nativity. All of them, except Thomas (who only comes from the 12th century) were celebrated early on in the Roman Rite. This year, none of them will be knocked out by the Feast of the Holy Family, that is the Sunday between Christmas and Epiphany.
St. John the Divine is the patron saint of wine, because when someone offered him a goblet of poisoned wine, he blessed it and it broke and a snake came forth. Today wine is blessed in honor of St. John. A blessing for it follows:
O Lord God, deign to bless and consecrate with Thy right hand this cup of wine and of whatever drink: and grant that through the merits of Saint John, Apostle and Evangelist, all who believe in Thee and who drink from this cup may be blessed and protected. And as blessed John drank from the cup of poison and remained completely unharmed, may, through his merits, all who drink from the cup on this day in honor of blessed John be rescued from every sickness of poison and from every kind of harm; and, offering themselves up body and soul, may they delivered from all fault. Through Christ our Lord. Amen.
Bless, O Lord, this creature of drink: that it may be a remedy of salvation for all who consume it: and grant through the invocation of Thy holy name that whoever will have tasted of it may, through Thy giving, experience health of the soul as well as of the body. Through Christ our Lord. Amen.
And the blessing of almighty God, Father, Son, and Holy Spirit, descend upon this creature of wine and of whatever drink, and remain forever. Amen.