How do I get it to recognise my bluetooth phone?

its the iphone, they still have not designed them to be "device friendly".
Still, Apple is playing their proprietary game where they refuse to make their devices compatible with others throughout the world. Having said that, the iPhone 4, is still only designed for voice to Bluetooth, handset to apple/mac interface, and for streaming music to compatible stereo Bluetooth headsets. I apologize for the not so good news, but apple still refuses to impliment software that makes this devices accessible from most other handheld devices.

Set phone permanantly visible

This process is not considered downloading but transfer, because you already have the music downloaded to your computer. You will need either Bluetooth or cable connections to connect your phone to your computer in order to make the transfer Bluetooth needs no cables but a little slower than cable connections. Connect your phone to your computer using the phone cable. or pair the computer Bluetooth with the phones Bluetooth this is easy if you already have Bluetooth on your computer such as if you use wireless keyboards and mouse, after select the songs you like to transfer and send them to a specific folder on your phone.

open bluetooth setting & set its visibility to all by checking( turn device on )box & ensure your phone's visibility is also shown to all

ya i have bought bh 505 yesterday and i am using samsung wave s8500...i have connected my phone with bh 505....its very easy...while turning on your bluetooth headset you have to press and hold for long time till a blu light appears then you turn on bluetooth in your phone and search...it will recognise and pair the device...thats alll ucan use it now...itss awesome....

If you mean that your iPhone won't recognise any bluetooth even with a bluetooth headset then there is definetly something wrong with the iphone that apple will have to deal with. If you mean that it will not recognise any other devices like printers, other mobile phones other than those from the apple brand,computers, the iphone bluetooth was never meant to work with other mobiles or to transfer files between other devices. It is a pain but there is no way of getting around this.

Bluetooth on the iphone only recognises other iphones or bluetooth devices such as the handsfree in your car. It will not find other mobile phones with bluetooth. Another scam for apple to get everyone to buy their fones I assume.

have a check at the bluetooth settings... have ur phone in the visible to all mode 

Please check whether your Phone is Hidden Mode.

Go to Bluetooth settings >> Visibiility >> Hidden (make it show to all) your issue should resolve

is the bluetooth set to always visible on your phone if not try that