Commercial command line utility for transcribing voice memos to text?
I doubt you can find command line commercial application.

You can better use some open source library like pocketsphinx http://cmusphinx.sourceforge.net

To transcribe a file you can use latest version 5prealpha:

   ffmpeg -i file.mp3 -ar 16000 -ac 1 file.wav
   pocketsphinx_continuous -infile file.wav -logfn /dev/null


that should give you an automated transcription. To increase the accuracy you can adapt to your own voice.