I've tried both iTM MCU and AC-7 Control, both of which are available in the Apps Store.
iTM seems to have a much harder time maintaining a connection (tested on XP 32 bit). AC-7 will not record remotely unless you hit play first, then record (tested on Windows 7 64).
Both require services to be installed on your windows machine. It takes a quite a bit of setup to get Audition to recognize the controls. You have to configure Audition to accept the midi signal as transport control. However, not all transport controls have corresponding MIDI assignments or keyboard shortcuts.
I wouldn't necessarily recommend either one but, if I had to choose, it would be AC-7.
Keep in mind that both your computer and the iPhone require access to the same network. That said, having networking turned on during an audio session can cause serious performance problems. There are dedicated wireless hardware solutions that connect directly to your computer. Frontier Design's Tranzport works up to 33 feet. I have not tested it.