This is a Marvell W8686B22. The Marvell W8686 family is a 802.11a/b/g WLAN system-on-chip. The iPhone has a W8686B13, which is likely a very similar part.
We did not find the CSR Bluetooth chip that the iPhone has. However, there are several Apple-branded chips that we didn't identify, so we cannot completely rule out the presence of a Bluetooth chip.
From what we are told, a Bluetooth antenna (if it existed) could be integrated into a PCB like this one, making identification difficult. The 'RF1UB' marking on the back of the board indicates that it's been designed for RF, and probably tested at frequency. So, while we don't see evidence of a Bluetooth antenna, we cannot rule out its existence.