So by compatible you mean that you've seen a Bell device display the letter "H" on the Rogers' network?
The logo being displayed by each carrier is purely branding/marketing. It doesn't matter if you see H+, 4G or 3.5G, it all depends on what cell network your carrier is running. In this case Bell and Rogers run an equivalent HSPA+ network on the same frequencies. This means you run a H+ device on the other carrier and will work without an issue.
To specifically answer your question, YES, you will see H+ on a Rogers phone on Bell's network since they both brand HSPA+ as "H+".
That was one of my concens too. I better call Bell and find out their policy. I was under the impression they usually accept the new owner but I don't kow about Bell.
They have provided you with false information as they along with Telus and Rogers sell unlock codes for their devices. They gouge their clients with a $50 unlock plus you must qualify for it.. Plus they will not know it is unlocked.
Why would they provide disinformation on that? I called back and spoke to a manager, not to a rookie and asked if I could get my phone unlocked by Bell so that I could sign up for a 3 year plan with them he said they don't unlock phones. I then called Wireless etc and they said it voids the warranty on Bell devices they sell.
Not true unfortunately. Wireless etc is a authorized dealer and does not know their policies. Bell offers unlocking for all their devices except for the iPhone for $75. This is aligned with Telus, Virgin, and Rogers as well. The stores don't unlock their devices. Carriers only unlock if you are a current customer.