Hi Pooja,
In this case the portchannel will directly connect to 2 ports on the same Nortel switch or diffrent switch. If its on the same switch, then we shouldnt have any problem and it should work OK with all the interfaces as layer3.
Generally nortel doesnot use STP on the ports enabled for SMLT. So what I am thinking as if they want to use the port bundle from 7200 to different nortel switches. What needs to be checked is what type of links are being use for the SMLT. layer2 or Layer3? If its Layer 2 at nortek side and layer 3 at 7200, then you might get into problems.
HTH,
-amit singh