Are T-Mobile 3G bandwidth compatible with Telus phones

[Charlesinsat]

I would like to know if a Telus Canada phone will work on T-Mobile's 3G network?

I am completely confused about these different bands and frequencies. I am looking to purchase the Motorola Milestone (GSM version of Droid) that will be released on Telus. I know it will work on AT&T 3G network but I hear T-Mobile uses a different one?

Also, I grandfathered the $19.99 unlimited BIS. Will the Milestone work with this plan since it's a smartphone or do I have to change my plan to something else like the $30 data plan?

If anyone have any insight to these questions, I'd appreciated very much.