My iPhone 4 was jailbroken but NOT unlocked. It was a tethered jailbreak via redsnow. Then I ran GreenPois0n and untethered it and it worked flawlessly.
My sister has a 3GS and it is tethered jailbroken with redsnow and unlocked via untrasn0w and has the iPad baseband of 6.15.
If I run GreenPois0n on my sisters phone, will it do anything to my current unlock?