Unless I'm mistaken, support for the Bluetooth API is not related to whether a phone is MIDP-1.0 or 2.0. An MIDP-1.0 phone may support BT-API, but it is not a requirement. It is not a requirement of MIDP-2.0 either.
The 6600 supports MIDP-2.0. You will find specifications for most Nokia phones on the Forum Nokia website, including details of which MIDP version and which APIs they support.