Check the gentle alarm forum. There is a tasker section that lists some intents. Here are the snooze and dismiss intents.
Gentle Alarm (780)
A1: Send Intent [ Action:com.mobitobi.android.gentlealarm.ACTION_SNOOZE Cat:None Mime Type: Data: Extra: Extra: Extra: Package: Class: Target:Broadcast Receiver Continue Task After Error:On ]
A2: [X] Send Intent [ Action:com.mobitobi.android.gentlealarm.ACTION_DISMISS Cat:None Mime Type: Data: Extra: Extra: Extra: Package: Class: Target:Broadcast Receiver Continue Task After Error:On ]