I like the idea of the proposal because I enjoy wine. The current quantity of traffic and followers in Homebrewing certainly would not be enough to support a dedicated site.
I think one of the keys to success is understanding what current SE traffic might look like to support the site as well as how the site would attract traffic once it is in Beta.
I do not believe that homebrewing covers the landscape of wine. The vineyards, regions and types of wine seem to go against the scope of homebrewing as well as what was mentioned prior, pairings and such.
I would follow it but would be concerned about how to attract users initially.