The bus stops are available in the SMS fields,
First choose the period by the Reports Tab. Create a query to choose who will get the SMS.
Then you need to choose Parents Per Student by the SMS Select tab.
Then you need top remove the check box of No Addl Merge Field from the SMS tab. Now click on Send SMS.
You will now have the fields BusNamePM And BusStopPM And BusTimePM.
Before sending its best to click Export to Excel and review in excel exactly whats being sent to each parent,