I know this area quite well having travelled there extensively every year for the past five years and always using public transport.

The area, which is generally called Frankenland or Fränkische Schweiz, claims to have the greatest density of breweries in Europe (and possibly the world). This is roughly the triangle between Bamberg, Bayreuth and Nürnberg. It is also home to what are probably some of the best beer gardens in Germany. Which is why there are sites such as: http://bierfranken.eu/, http://www.bamberg-guide.de/bamberg/bierundbierkultur/, http://www.bierkeller.de/, http://www.bierregion-franken.de/ and this one: http://www.franconiabeerguide.com/default.asp.

The VGN does provide local transport, but not only in Nürnberg, but in exactly the region where the beer brewery/beer gardens are located: the triangle made by Bamberg, Bayreuth and Nürnberg. You can get a partial idea of their service area here:
http://www.vgn.de/ib/site/documents/...t_Prospekt.jpg

They offer special buses and brochures for those interested in exploring beer gardens and breweries. For example, Freizeitlinie 343 - Bier-, Brotzeit und Burgen-Express, Freizeitlinie 230 - Brauereien-Wander-Express, Freizeitlinie 977 - Wandertipps Brauereien-Fachwerk-Express and Freizeitlinie 265 - Hallerndorfer-Keller-Express.

In brief, if you want to explore the wonderful beer gardens, pubs and breweries of the beeriest part of Bavaria and you appreciate the convenience and cost-savings of public transport (not to mention your point of "alcohol tourism"), you need go no further than the VGN website.

But, beware: if you switch the VGN site to English, most of the interesting and helpful features (such as the special buses), will disappear.