I can corroborate that having the Firewall on/off seems to make no difference.
I've recently experimented with my MBP 15" Retina (June 2012) and my iPhone 5s (Oct 2013), and I'm having the same issue as many others, where my MBP can see my iPhone but my iPhone CANNOT see the MBP (everything is always set to "Everyone").
I happened to discover the WEIRDEST 'workaround.' It's unlikely to be helpful for most but perhaps it'll mean something to someone: While troubleshooting, I activated the AirDrop folder on my wife's MBP 13" Retina (Oct 2013) to see if it would work on her computer - and it did, perfectly! My iPhone could see her MBP 13" Retina.
Here's the weird part though: The moment my iPhone saw her MBP 13" it was simultaneously able to see my MBP 15" !!! And I was able to transfer the file just as easily. But when I closed her MBP 13" and started the process over on my MBP 15", once again, no dice. I tried the experiment again and it worked just as before.
So in other words, my workaround is ... wait for it ... I need to open and activate the Airdrop folder on my wife's MBP 13" Retina so that my iPhone 5s can see my MBP 15" Retina. Weird, eh? :\
I really hope I don't need to do that for the rest of eternity.