Title 40, Chapter 9.11 details permit requirements for transporting alcohol within the Commonwealth. Note 9.11(b)(3) which exempts transport for "personal use."
9.11. Transportation for hire.
(a) Except as exempted in subsection (b), a person who transports liquor, malt or brewed beverages or alcohol for hire within this commonwealth shall obtain a Transporter-for-Hire License, Class A, a Transporter-for-Hire License, Class B or a Transporter-for-Hire License, Class C, from the Board.
(b) Liquor, malt or brewed beverages or alcohol, may be transported for hire without a Transporter-for-Hire License under the following conditions:
(1) If the alcohol in question is ‘‘denatured,’’ as specified in the Liquor Code.
(2) If transportation is accomplished by scheduled common air carriers of mail and passengers; or by common carriers by railroad, subject to regulation by the Pennsylvania Public Utility Commission; or by transporters-for-hire who transport liquor, malt or brewed beverages or alcohol, under contract with, and as agents of, common carriers by railroad, under railroad tariffs, railroad bills of lading, railroad regulations and railroad responsibility and direction, provided the main transportation of the liquor, malt or brewed beverages or alcohol, is by rail and the agents perform only a collection and delivery service as part of the rail transportation, and further provided that certified copies of the contracts of the agents are filed with the Board.
(3) If the liquor, malt or brewed beverages, or alcohol in question are for the personal use of, and not for resale by, the transporter.
(4) If transportation is by licensees of the Board whose licenses or permits authorize the transportation of liquor, malt or brewed beverages or alcohol in the regular operation of their licensed business.
(5) If transportation is by persons who transport liquor, malt or brewed beverages or alcohol, through this Commonwealth commercially and not for delivery therein:
(i) The operator of the vehicle shall have in his possession at all times while in this Commonwealth, an invoice and a bill of lading or waybill (showing the brand name, size and number of containers of liquor, malt or brewed beverages or alcohol so transported), which shall be produced for inspection upon the request of an authorized police or enforcement officer of this Commonwealth.
(ii) The cargo must remain intact and upon the same vehicle or conveyance while in this Commonwealth, unless prevented by an accident or other similarly uncontrollable circumstance.
I'm not a lawyer, but in my reading the wording is vague enough that a zealous LEO and/or county prosecutor might want to test the limits of the Legislature's intent as to whether or not distribution of homebrew at a wedding constitutes "personal use."
It would seem, however, that Title 47 gives the homebrewer a reasonable exemption for weddings in the wording that authorizes them to brew for personal use:
Pa. Stat. tit. 47, §4-492
It shall be unlawful–
(1) Manufacturing Without License. Except as provided herein, for any person, to manufacture malt or brewed beverages, unless such person holds a valid manufacturer’s license for such purpose issued by the board. Malt or brewed beverages may be produced by any person without a license if such malt or brewed beverages are produced not for sale and total production does not exceed 200 gallons per calendar year. Malt or brewed beverages produced in accordance with this paragraph may be used at organized affairs, exhibitions, competitions, contests, tastings or judging provided it is not sold or offered for sale.
Clearly, HomebrewCon distribution is allowed, and so as long as the wedding is an "organized affair" I guess it'd be OK, but like I said, I'm not a lawyer.