Just as an update, it has been more than ten days since one pair of flights and they didn't post automatically this time. I chatted with a rep about this (who initially told me that regrettably points flights don't earn tier credit) and provided them with the link. ( https://www.southwest.com/denveroffer/ ) The response was, "Thank you for sharing that link, I had no idea about this offer. I will have to request our Loyalty Assurance team to handle the account update. One moment while I submit that." I have a case number now, not sure why flights from three weeks earlier posted automatically but these did not. I suspect I'll have to repeat the process for the pair from last week. Good luck to you!!