Michael,
I will assume you are using the latest versions of iOS, LR Mobile, and LRCC. If not, you will need to update. I also assume you are adding RAW files from the Camera Roll on you iPad. If so, follow the steps below:
1. In LR Mobile create a new collection and ADD the photos (RAW) from the camera roll.
2. Staring here you can edit those photos in LR Mobile as much as you want.
3. LR Mobile will sync smart previews and all edits to the Creative Cloud and they will be available on all of your devices (including iPhone if you have e LR Mobile installed there.
4. You iPad will also upload the original RAW files to the cloud, then down to you desktop (the RAWs will not stay in the cloud). Depending on the size, number of files, and you wifi connection this can take a good while, i.e. hours if there are a lot of them.
5. You will be able to find you RAW files on you desktop after all of this is completed. Be sure to check this before the last step;
6. Once all of this has taken place, you can deleted the original RAWs from you cameral roll on the iPad. The photos will remain in the sync'd collection. and can be edited from either device.
7. I would strongly recommend you test all of this out before trying it with important photographs.
Woody