Hi,
not sure what micro-BFD is exactly, but the IETF mode for BFD over bundle has been introduced very recently in the CRS in 5.3.1
http://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r5-3/general/release/notes/reln_531crs.html#concept_048396DA6E5A48ECBB5DFE475EC90966
Before, it's a proprietary implementation.
Cheers,
N.