Cal. Bus. & Prof. Code § 25503.30

(a) Notwithstanding any other provision of this division, a winegrower or one or more of its direct or indirect subsidiaries of which the winegrower owns not less than a 51-percent interest, who manufactures, produces, bottles, processes, imports, or sells wine and distilled spirits made from grape wine or other grape products only, under a winegrower’s license or any other license issued pursuant to this division, or any officer or director of, or any person holding any interest in, those persons may serve as an officer or director of, and may hold the ownership of any interest or any financial or representative relationship in, any on-sale license, or the business conducted under that license, provided that, except in the case of a holder of on-sale general licenses for airplanes and duplicate on-sale general licenses for air common carriers, all of the following conditions are met:
1. (1) The on-sale licensee purchases all alcoholic beverages sold and served only from California wholesale licensees.
2. (2) The number of wine items by brand offered for sale by the on-sale licensee that are produced, bottled, processed, imported, or sold by the licensed winegrower or by the subsidiary of which the winegrower owns not less than 51 percent, or by any officer or director of, or by any person holding any interest in, those persons does not exceed 15 percent of the total wine items by brand listed and offered for sale by the on-sale licensee selling and serving that wine. Notwithstanding paragraph (1), wine sold pursuant to this provision may be purchased from a California winegrower so long as the wine purchased is produced or bottled by, or produced and packaged for, the same licensed winegrower that holds an interest in the on-sale license and such direct sales do not involve more than two on-sale licenses in which the winegrower or any person holding an interest in the winegrower holds any interest, directly or indirectly, either individually or in combination or together with each other in the aggregate.
3. (3) None of the persons specified in this section may have any of the interests specified in this section in more than two on-sale licenses.
(b) The Legislature finds that, while this section provides a limited exception for licensed winegrowers, that limited exception is granted for specific purposes, and that it is also necessary and proper that licensed winegrowers maintain the authority granted under this division to sell wine and brandy to any individual consumer or any person holding a license authorizing the sale of wine or brandy.
(c) The Legislature finds that it is necessary and proper to require a separation between manufacturing interests, wholesale interests, and retail interests in the production and distribution of alcoholic beverages in order to prevent suppliers from dominating local markets through vertical integration and to prevent excessive sales of alcoholic beverages produced by overly aggressive marketing techniques. The Legislature further finds that the exceptions established by this section to the general prohibition against tied interests must be limited to their express terms so as not to undermine the general prohibition, and the Legislature intends that this section be construed accordingly.