Jared,
The simple answer is that promis-e is designed for the wire number text to follow the direction of the wires, otherwise it is assumed there would be constant collisions between text and wires running parallel. The correct procedure would be to right-click over the wire number and select 'Text Settings' but you will not find a rotation option here.
The only workaround (however I would really not recommend this) would be to select the 'Element Info' command from the 'Primary Tools' tool bar, and select the text. You should then see all of the PowerDraft settings for the text and can extend the bar for Geometry' and change the rotation. Be aware however that promis-e will not have this information in its project database and I found that after rotating the wire text via this workaround, the wire number disappeared after moving an adjacent symbol along the wire and changing the wire length.
Summary, its not possible at the moment to have the wire number text rotated manually away from the rotation of the wire.
John.