It's probably easier done at the phone level. Turning BT off and then back on when you want. Many phones have a silent or "airplane" mode that is 1 or 2 clicks away.
You can go into the BT system settings and remove your phone from being connected through sync. I'm guessing attaching it would just be like doing it the 1st time. May have to download your contacts again. Don't know though.
2010 F150 XLT SuperCrew, 5.4L V8, 6.5' bed, 3.55LS, Tuxedo Black, Tow pkg, Sync