I find it hard to find unbiased or not financially incentivized/motivated information about the Credit Card-based travel portals which most customers with lifestyle cards are incentivized to use. I thought I would make a wiki here with information that others can update that hopefully will help people use these portals.

There are some generic items that I won't really cover such as card-specific limited time unique offers that almost all of them do from time to time and any private inventory for their travel items which they all have certain negotiated programs. This means you need to check all the portals where you have eligibility to use, special card offers or cards with ongoing points bonuses. You also need to "flip" the primary card on each travel portal to "activate" special pricing.

Finally, all of the travel portals have filters that are not obvious. Maybe it is due to a profit margin requirement on a given item for booking, maybe it is certain classes of airfare or hotels or other items they don't sell. Always use a meta-travel site (Google Travel, Kayak, Trivago, etc.) and the travel provider directly to compare pricing and options.