I think you would be able if, in addition to what you said above, that:
A) It's a US lens. I'm not sure how Tamron does it but with Nikon it's quite obvious if it is a US lens or not.
B) You send all the paperwork from the US. I'm not sure if the rebate processing people are smart enough to notice a Canadian stamp on the envelope. If they do they may invalid your rebate.
C) The receipt you submit is from a store in the US. Again, it depends on how keen the rebate processing folks are in recognizing a Canadian receipt.
|Bianca Buitendag-7809 by vbuhay|
|Sunrise in Paradise by OB Foto|
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|The Battle for the Lead by Photo Pete|
from Bicycle sports
|Cecelia's Eyes by Madeleine Hart|
from - Jenny from the Block - (Colors that pop + A white Border)