Well shit I was wrong to one extent. It would matter if he was driving the vehicle at the time. But the court could still argue he obtained alcohol at the club and then drove home after getting thrown out, could cause some issues.

(2) For purposes of this chapter, an accepted plea of nolo contendere to any violation of Code Section 40-6-393 or 40-6-394 shall constitute a conviction.
(e) The driveŕs license of any person under 21 years of age who is convicted of unlawful possession of alcoholic beverages in violation of Code Section 3-3-23 while operating a motor vehicle may be suspended for a period of not less than 120 days. At the end of 120 days, the person may apply to the department for reinstatement of said driveŕs license. Such license shall be reinstated only if the person submits proof of completion of an approved DUI Alcohol or Drug Use Risk Reduction Program and pays a restoration fee of $35.00 or $25.00 when processed by mail. For purposes of this subsection, a sentence under subsection (c) of Code Section 3-3-23.1 shall not be considered a conviction, and the driveŕs license of such person shall not be suspended, provided that such person completes a DUI Alcohol or Drug Use Risk Reduction Program within 120 days after sentencing.

This is what you would face if charged with underage possession.

3-3-23.1.
(a) It is unlawful for any person knowingly to violate any prohibition contained in Code Section 3-3-23, relating to furnishing alcoholic beverages to, and purchasing, attempting to purchase, and possession of alcoholic beverages by, a person under 21 years of age.
(b)(1) Any person convicted of violating any prohibition contained in subsection (a) of Code Section 3-3-23 shall, upon the first conviction, be guilty of a misdemeanor, except that any person convicted of violating paragraph (2) of subsection (a) of Code Section 3-3-23 shall, upon the first conviction, be guilty of a misdemeanor and shall be punished by not more than six monthś imprisonment or a fine of not more than $300.00, or both and except that any person convicted of violating paragraph (4) of subsection (a) of Code Section 3-3-23 shall, upon the first conviction, be guilty of a misdemeanor of a high and aggravated nature.
(2) Any person convicted of violating any prohibition contained in subsection (a) of Code Section 3-3-23 shall, upon the second or subsequent conviction, be guilty of a misdemeanor of a high and aggravated nature, except that any person convicted of violating paragraph (2) of subsection (a) of Code Section 3-3-23 shall, upon the second or subsequent conviction, be guilty of a misdemeanor.
(3) In addition to any other penalty provided for in paragraphs (1) and (2) of this subsection, the driveŕs license of any person convicted of attempting to purchase an alcoholic beverage in violation of paragraph (2) of subsection (a) of Code Section 3-3-23 upon the first conviction shall be suspended for six months and upon the second or subsequent conviction shall be suspended for one year.