In order to get your wireless Bluetooth Headphones for iPhone to work with your iOS device, the device must be equipped with Bluetooth A2DP. A2DP is simply the version of Bluetooth that allows for stereo sound.
Here is a list of iOS devices that are compatible with Bluetooth A2DP and Bluetooth enabled headphones.
iPod touch 4th generation
iPod touch 3rd generation
iPod touch 2nd generation
All of these devices also have AVRCP or Audio/Video Remote Control Profile which allows you to control the volume, tracks, and other functions directly from your wireless Bluetooth Headphones if so equipped.