I'd like to add contacts to my mac, but only sync the contacts with phone numbers to my iphone can I make this definition using soocial?

Pete!

In the near future you will be able to tag your contacts for syncing to the different devices or engines. So the direct answer to your question i guess is: no, not yet.

I don't know how you have set up syncing right now but It sounds like you sync your Mac with Soocial ad your Iphone with your Mac.

You can also sync your Iphone over the air with an application called synthesis:

Check this topic:
http://getsatisfaction.com/soocial/to...