You cannot consume beer from an opponent’s Brewery unless it is connected to the location where the beer is required.

This is supported by the following rule:

• "Beer may be consumed from any of the following sources:
  1. Your unflipped Breweries. These do not need to be connected to the location where the beer is required.
  2. An opponent’s unflipped Brewery. These must be connected to the location where the beer is required."

Source: Page 8, under "Consuming Beer".

Therefore, connection always matters for opponent breweries when consuming beer. Only your own Breweries can provide beer without a connection.

Source: Core Rulebook (pp. 10, 12, 8, 9)