Can I log my military training time as PIC, if I have a PPL?
For FAA purposes you can log PIC time in the T6 because you hold a license in the airplane, single engine, land category and class.  However, the USAF might not see it that way.

Since you do not have an FAA license for the category and class multi engine land, you can only log PIC time for your solo flights in the T38.