The example provided by SiqinBilige shows latin text running down the right side of vertical Mongolian text - which seems logical, since the order of Latin letters follows the flow of the Mongolian text.

It also results in the ruby text appearing above the mongolian when the mongolian is displayed horizontally. Which also seems logical.

Does Chinese annotation (if it is used?) run down the same (right) side? Are there occasions where the ruby text appears to the left?