As good as Root Beer Tapper was, being a more kid/teenager-friendly version of the original Budweiser-licensed Tapper (which itself benefited from having its cabinet go so far as to resemble an actual bar, down to the brass footrests, ashtray and drink holders, and beer taps as game controls), I would still hint at the Root Beer version as far as getting a similar endorsement, perhaps from that of A&W, being a famous brand of root beer since 1919.
If such a license ever went through, I could also hint at A&W root beer sales going up as a result of the promotion. I know that A&W's then-mascot, the Great Root Bear, also appealed to kids and teens.
An alternate version of Tapper was released in which the drink was that of Mountain Dew. This mostly applied to all home ports of the game excepting the ColecoVision version, which went for the root-beer version.
So, folks, do you think that Root Beer Tapper could've benefited from an A&W promotion? If so, this game could've been found at some A&W All-American drive-ins, and all stores that sell A&W root beer. I'd even think of certain high-score contests where the player with the most points gets a free A&W root beer float.