I've tried to bind the Alarm Pipeline properties of an alarm directly to a string parameter property.
I know I've got the correct string because I double checked by creating a "normal" binding, directly to the alarm pipeline that I want the alarm the enter.
Manually toggling it into the alarm state and use the binding on the Alarm Pipeline I get nothing in the alarm pipeline.
Changing the Alarm Pipeline to be static and toggling it into the alarm state I get the alarm in the alarm pipeline.
Edit: just did it again, and it seemed to work. Maybe this has to do with when exactly the alarm enters the pipeline. I restored this from a backup and the tag has been in alarm since the start of the gateway. Maybe it needs to see that initial trigger for it to enter the pipeline.