Won't just doing a complete restore from Time Machine onto your iMac recover everything you need? Or is there some reason you don't want to restore all your settings, documents etc?
Anyway If I am understanding correctly and you don't want to restore everything from the Time Machine backup onto your new machine, but you do want to carry on syncing your iPhone same as before, then you just need the whole iTunes folder which is at /Users/username/Music/iTunes. This contains the library, music, phone apps, etc. It also contains the information to tell iTunes which devices it previously synced with, so it should just sync with your phone as if nothing had happened. It will make a new iPhone backup the first time you sync, so you don't really need to worry about the phone backups. However it won't work very well if you had things in the library which are outside of that folder, for example music elsewhere which was in the library.
I've never actually restored anything from Time Machine yet so can't help with the actual mechanics of how it works. A friend just got a new MBP and used some 'restore from Time Machine' option when setting it up and that apparently worked very well, effectively making the MBP the same as his previous MB with no hassle. That's what I would do rather than try to recover individual things.
