No, Sonar 2, 3, and 4 do not provide ASIO positioning protocol timecode sync. To sync to SMPTE and ADAT sync, you must have a MIDI device which translates SMPTE or ADAT sync into Midi TimeCode (MTC).

Please note this has nothing to do with Word Clock Sync between digital devices and audio hardware, which Sonar is perfectly capable of doing. (For example, syncing an audio device in sonar to external 44.1k digitally over S/PDIF, TDIF, ADAT lightpipe, AES/EBU, etc.)