amex business starwood card (most valuable points but only $100K limit)
+
diners club charge card / amex business gold or platinum

http://www.dinersclubus.com/dce_cont...ewardscompared
diners club / amex comparison

for starwood the cardholder would have to redeem points for others

for amex gold/plat any additional cardholder can be authorized to make membership reward airline transfers or other redemptions

for diners club, i dont know how it works