Home brew? Homebrew? Winemaking

Pretty much all commercial wine is fermented with wild yeast....they are present on the skins of the grapes....also the traditional method for our UK ciders.

San Fran sourdough? Is it really that special.....it's ben made in France. Germany and most of Eastern Europe for centuries...even in my flat!

Most commercial wine makers will add yeast to get slow fermenting wines going and enhance depth of flavour, aromas etc.
This is where the majority of your floral notes etc. in wines come from.
I'd say 90% of "new world" wines get made this way.