Except for this strange FAA arrangement, the only time that two people can claim flight time in a single-pilot aeroplane (other than when one is an instructor or examiner and the other a student or candidate) is if the state of registration requires it to be flown by two pilots or if it is operating under an AOC or similar arrangement that requires it to be flown by two pilots. Neither of these applies in your case and only the time that you are actually flying the aircraft as PIC can be claimed towards any JAA (or DGCA) licence or rating. For the other 150 hours you will be a passenger.