Now that AC has extended the time frame for selection of Altitude Select Privileges to November 2018, I'm wondering about how waiting to select might affect Altitude Bonus miles option. Does anyone know when those miles are calculated and applied? If I wait until later in the year to select that benefit, will I only get bonus miles credit for the miles accumulated after I make the selection? Will I have to request credit for the previous portions? Is it automatic? Or does AC typically apply the bonus miles at the end of the year calculated based on all accumulated miles?