Since Halide uses the photo library, if you use iCloud Photos, then the images will get synced to your Mac and you can use RAW Power there (or Photos). iCloud will send the original RAW.
If you aren’t using iCloud Photos, then you can import them from your phone to the Mac. Photos will import the RAW as well. There will not be any conversion to JPEG as long as you use Photos to import the images (vs. using share or some other means).
If you start in RAW Power for iOS and then save as non-destructive, you can continue editing on the Mac with RAW Power. That will work when using iCloud, which will sync both the editing data and original image. If you don’t use iCloud, then it’s “possible” to import the editing data from iOS, but Photos is very unreliable in this regard (I have no idea if it even works with the latest OS – it’s that sketchy).