Late reply, but it depends on what you are trying to send:
- For normal Pokemon, you only need to restore the Dream Radar save since they can be sent to the same game multiple times.
- For sending Legends (i.e. the genies) to different saves (i.e. different carts), you only need to restore the Dream Radar save.
- For sending Legends to the same save file (that have already received the legend in question), you need to restore both the game save and the Dream Radar save.
The legends can only be sent once per Dream Radar save, and to a single game only once (hopefully that makes sense). So if you send over Tornadus to your W2 cart but mess up, you would have to restore both the game and the Dream Radar to try again.