Hi hkgige,
Currently Vision only supports decoding bayer images to RGB32, not RGB64, so there is not much advantage to sending bayer formats >8bit. We do support unpacked 10 and 12 bit bayer formats but the result is still only 8-bits per color plane (RGB32). Every camera that has supported 10 and 12-bit packed bayer formats I have seen has supported 8-bits as well, so there was not much lost by not supporting the 10/12-bit packed modes.
We do have an open request to add higher bit-depth bayer decoding (to RGB64) which does necessitate the packed bayer formats to achieve the best efficiency, so it is likely we might support these at some point.
Eric