Synching, making Iphone the primary

Primary what? You can sync as many devices as you want to the same iTunes account, there is no limit. You can have the same content on each device or different content, the choice is yours. iTunes will keep everything straight, by device, upon subsequent syncs. There is no such thing as "Primary".

Contact syncing is bi-directional. So, with iTunes not running, launch iSync from your applications folder, under preferences, "Reset Sync History". When finished, re-boot your computer. See if doing this fixes things.

PS I downloaded iSync. Followed the instructions as far as I could (turned on Bluetooth in order to make my iPhone 'discoverable') but now the phone won't sync.I have to go to the Bluetooth Setup Assistant to make it discoverable. Then I get the message: To continue pairing, make sure the number below is displayed on the device you're pairing' The number below doesn't appear, nor does my iPhone sync any longer.So nothing's happening at all. Let alone my being able to now move contacts FROM my MacBook Pro TO my iPhone. Which was the original reason. Any ideas what I can do now? iSync asked me to make the computer discoverable and my computer then

I tried this too, but it didn't work. Contacts I added on my iPhone have been transferred to my computer.Is there anything else I can try please?