Do my iCloud-enabled devices have to be on the same Wi-Fi network to sync?

I'm going out of town and having someone come over once a day to check on my cat. I'd like to set up a motion-activated feature on my iPad, which will save photos to the photo stream. Ideally, I'll be able to access these photos from my iPhone while I'm gone. I'm just not sure if the photo stream will sync with the devices without being on the same wireless network.

(I'm already looking for an app that will just email the pictures, but I'm not having much luck.)

You have to be on the same Wi-Fi network. If so, you can use wireless transfer app to share files between multiple devices.
http://www.android-to-iphone.com/download.html