jw99, I think the short answer to your question is no, Marriott does not have a comparable program that rewards points/miles simultaneously in two programs. That said, you can transfer Starpoints at a rate of 1 Starpoint for 3 Marriott Rewards points. So, in essence, you can earn Marriott Rewards points by earning Starpoints by flying Delta planes
jw99, yes you can earn miles or points, but not both as in the case of SPG. Additionally, as a Platinum Marriott Rewards member you can enjoy Silver status with United as a reciprocal benefit. However, neither of those seemed to align with your question as they don't mirror the concurrent earnings benefit at SPG.