Q: I'm able to pair my iPhone with Macbook air

For what are you trying to pair your iPhone and MBA to do?  Bluetooth file transfer is NOT supported.  iPhones have NEVER been able to pair with computers except for the sole purpose of tethering.

Having your computer use your iPhone's internet/data connection.

What about pairing the two to use the app "Keynote Remote"? I'm having the same issue where my MacBook Air pairs successfully with the iPhone but then the iPhone can't "see" my MBA. I want to pair them so I can use the Keynote Remote app. I do realize the app works over WiFi and I've successfully done that. However, if I present in an area without WiFi, I'd really like to be able to use Bluetooth. The Keynote App says it can use either.

Never mind, I just found out the answer. An Apple Support Article (http://support.apple.com/kb/HT3325) says "You cannot use Keynote Remote via Bluetooth with a Mac."

Kinda defeats the purpose (at least for me) - bummer!