Yes, you can have two numbers for a users but not the same way as in Skype for Business where you could have a PrivateLine with a separate number assigned to the user.
In your SBC rewrite the incoming number to the number that you have set to the user in Teams. So if you set number +1555123000 to your user in Teams and in you SBC you set so that calls that come to the secondary number is manipulated to +1555123000 in the INVITE to Teams. For outbound calls the number presentation will be +1555123000.
