JLinked doesn't have the ability to use JomSocial's registration flow right now. We did just add a
Choose Your Own Registration Flow
option in JFBConnect v5.2.
The next major release of JFBConnect will incorporate all of JLinked's features and will offer the same registration flow options that you're looking for. That release will be out in early 2014. At that time, JLinked will be deprecated, and all subscribers to it will be transferred to JFBConnect.
Unfortunately, for now with LinkedIn registration and JLinked, there isn't an option to directly use the JomSocial registration flow. What you can do is set the New User Redirection to go to the user's Profile and have them edit it after their account is created. That gives them the option to update any values as necessary after their account has been automatically created.
I hope that helps explain, but if you have any other questions, just let me know.
Thanks,
Alex