Congratulations on finishing your certification. I dived with Bubbles Below and Linda a few years ago, and I thought they did a great job.
Just in case anyone else is using this thread for information....
Your LDS should be able to give you a Universal Referral form that will allow you to complete your certification with any agency recognized by the RTSC.
The RSTC is not really connected to the Universal Referral program. PADI is an RSTC member, but it does not FORMALLY participate in the universal referral program. NAUI is not a member of the RSTC but it does participate.
PADI is the only agency I know of (there could be others) that does not participate in the Universal Program on an official basis. They have a reason for it. In the Universal referral system, the agency/instructor certifying the diver is the agency/instructor who did the academic work and the pool skills. That person has never actually seen the student dive, and PADI feels strongly that the certifying agency/instructor should be the one who sees the diver perform in the open water. As I understand it, consultation with attorneys apparently suggested there could be liability attached to someone who certifies someone who is really not competent and who was clearly not competent on the OW dives.
To deal with the unfairness of an instructor doing that initial work and getting no credit for having done it in the agency system, PADI issues a half certification credit for the referring instructor. That is really important in places like Colorado, where over 80% of our students complete their certifications via referral.
IF a student takes a Universal Referral to a PADI site, PADI would prefer that a PADI certification be issued, but that site may choose to participate in the Universal Referral program instead. So a SDI referral form could be taken to a PADI resort and result in a SDI certification through the universal referral program, but that would be at the discretion of the resort/instructor.