The 2 are totally separate.
The points you receive for the purchase of the trip post on the statement (and thus on your AGR account) when that month's (when the purchase was made) closed/closes. If you made the purchase of an October 2014 trip in March 2014, the 2X posted for the purchase when your March 2014 closed, and the points 2X for the trip on October 1 will post after the trip is taken.
If you purchase a ticket on October 1 for a trip on October 1, the 2X for the trip will post after the trip occurs on October 1. The 2X for the purchase will post after the October statement closes - say on October 26!