How can I get text notifications on my 390 Plantronics bluetooth device from my Galaxy Prevail 2 if it has that feature?
I have tried my settings in my phone but it only has the option for call audio.
What else can I do?
If you're talking about Audio here (e.g. having notifications, alarms, etc. sent to your (Bluetooth) headset), you might wish to take a look at SoundAbout:
This app allows you to define which audio signal is routed where (even on certain conditions). I'm not sure how far the free version goes concerning Bluetooth, as the app description says Bluetooth behavior - (Pro version). To my understanding, those "behavior settings" only include specifics like "force to mono", but I don't use the app myself, and thus cannot tell for sure.