Lacto seems to be ubiquitous (just open your mouth).
Microbes don't really have a way to move around on their own. Despite that, they are carried around on things or water or float through the air. Thus, accurately saying where they may or may not be seems impossible... especially since there doesn't seem to be anyone tracking them.
Some people report finding plenty of Brett in their locales.
My suggestion is to start with some tree bark, flowers, and fruits. You may indeed find some Brett and/or Pedio (which is a type of LAB by the way).
My question to you is: how will you know when you've found one? Are you going to be isolating strains?
FWIW I'd find questions faster in the Wild subforum
Cheers