Nothing in this title shall apply to or prevent a hospital, as defined in *RCW
70.39.020, or a nursing home as defined in RCW
18.51.010, from offering or supplying without charge beer or wine by the individual glass to any patient, member of a patient's family, or patient visitor, for consumption on the premises: PROVIDED, That such patient, family member, or visitor shall be at least twenty-one years of age, and that the beer or wine shall be purchased under this title.