Here's what I found out in my travels: 1. If you have an Alaska Boardroom membership, you will get access to Alaska, AA, and DL lounges. You will NOT have access to BA lounges (or at least I was denied), although the Alaska web site states that "partner lounges" are available. You can bring family or up to 2 guests at no charge to Alaska and AA lounges. 2. If you have an Amex platinum, you can get a priority pass select card, which will get you access to AS lounges when flying AS. Alas, there are not many of those. The Amex itself will get you access to Delta lounges when flying DL (no guests). It will not get you access to DL lounges when flying AS, even if there is no AS lounge and the DL one is listed as a boardroom partner. In addition, you will be able to use Centurion lounges - they are great but few. 3. Priority Pass has a good number of lounges of varying quality. However, the "select" version that comes with Amex Platinum will NOT let you use United lounges, even when those are listed by Priority Pass.