I got a mortgage years ago with the late, un-lamented cheats at Countrywide (now part of the Bank of American and, hopefully, cleaned up) which offered 25K in AA miles. It was quite a struggle to collect as it turned out they took the cost of the miles out of the broker's commission (or, so he told me). But, the rate then was the same with or without miles. Now, it appears to not be so with miles being paid for by the borrower with a higher interest rate.

Apply for another bonus credit card and forget, IMHO, the mortgage miles.