As more and more of us are flying VX more and more, and have various lounge access programs, and VX doesn't have its own, it seems to make sense to have a consolidated place to look this all up. I find that I'm spending too much time figuring out the terminals of VX before a trip (I've only flown them a handful of times, with more in the plans), and figuring out what is airside/landside/behind the same secured area, etc. (Airside in other terminals/secured areas where you need another airline's gate pass because of a membership aren't really designed to be part of this. The whole idea is O/D/Connecting on VX)

(It will ultimately take moderator action to keep the top post correct with additional / updated information).

I'll bite, to start:

SFO

AA Admirals Club - Same Terminal, airside. A minute or two to any gate. Need AA membership or day pass

VS Clubhouse - Landside Int'l Terminal (A pier) $35 (purchased online or at ticket counter) - very limited hours, and only available to F, MCS, and Elevate members. Allow 15 minutes walk to T-2 security from lounge.

SEA

(All lounges are airside)
AS Board Room - Need AS or PP (Priority Pass) membership, or day pass. Approximately 10 minute walk to the VX gates.

UA United Club - B pier and N terminal gates. Need PP or UA membership, or day pass. B pier is a 5+ minute walk to gates. N - need a train or two and a walk (not recommended)

For the UA lounge at SEA, you need a PP that is not a financial company issued one (such as those for AMEX PLAT members).