California Code, Business and Professions Code - BPC § 23356.3

Notwithstanding any other provision of this division, an out-of-state winegrower, after notification to, and approved by, the department, may furnish American wine which the winegrower produces and bottles for wine tastings sponsored by a private nonprofit organization. This privilege shall be extended to winegrowers in those states which accord California winegrowers a substantially equal reciprocal wine tasting privilege. Certification by an appropriate state official of his or her state's reciprocal wine tasting privilege shall be included with the required notification.