I'm *pretty sure* if you put the phone on vibrate or silent, you'll still get a ring tone/sound/voice notification in your bluetooth headset. Have you tried it that way?
I've used many different headsets, including your T1 and other BlueAnts, and I'm pretty confident they always rang through to the headset (or spoke to you if it had that capability) even when the phone was set to silent or vibrate. I just checked it on my Plantronics M1100 with phone sound set to Mute. It didn't *ring* in the headset, but it did give me the voice instruction that I had an incoming call.