The 3x miles offer was for flights purchased on-line at aircanada.com between April 1 and April 30. (minimum spend of $225 per transaction)
The other offer was 3x miles (instead of 1.5) on gas, grocery and drugstore purchases posted to your April and May TD cc statement. Fine print says: "The promotion is open to Aeroplan members who have an Aeroplan-affiliated credit card tied to a sold account transitioning to TD and received the TD Welcome Series targeted communication for this promotion." These bonus miles have already posted (got 3200 miles instead of 1600). You also had to register your card for the Welcome Series.