Yes, any unused eligible bundle credits (Paid Course Entitlements) will transfer to MIT Learn. To access them, you must create an MIT Learn account using the same email address associated with the edX account for which you made the program bundle purchase on edX.
Your MIT Learn account will be issued Paid Course Entitlements, which will allow you to enroll in an upcoming session of its course at no additional cost. To do so, locate the desired course on your MIT Learn Dashboard and click its associated "Start Course" button. If you have an Entitlement for that course, you will be automatically enrolled in the next upcoming course session and upgraded to the Certificate/Verified (Paid) track.
Unfortunately, the MIT Learn Dashboard cannot yet display information about Program Bundle purchases or Paid Course Entitlements, so there's currently no way to see whether you have an Entitlement for a course other than attempting to enroll with the "Start Course" button.
If you believe that you should have a Paid Entitlement for a specific course, but clicking its "Start Course" button on your MIT Learn Dashboard does not automatically enroll you in and upgrade that course, please contact MIT Learn Support for further assistance. To ensure efficient support, be sure to provide your name, the email address associated with your MIT Learn and edX accounts, the name of the MITx program, and when you purchased its Program Bundle.