I have been interested in a similar question (my question was which program allow transfers to another person other than a family member) and started to put something together. I only know if the following so far and don't have all the info for them--
1) Amex-- limited programs allowed--diff. transfer rates
2) Diner--some programs
3) Wyndham---AA,others??
4) Chase sapphire---
5) Flex points----
6) others-------?????