The iphone is not a great reef camera due to its inabilities to white balance under high color temperature lighting and to shoot RAW format files. Least you think I'm Apple bashing, which I am guilty of frequently, it shares those lethal flaws with most if not all cellphones and many point and shoot cameras as well.
The inability to white balance properly is what results in the "too blue" pics. Combine that with blue led lighting, and typically the blue channel is entirely blown out, such as in the last shot.
Zooming with your iphone results in a degredation of image quality. It's a fixed lens so it's a purely digital zoom which simply takes the existing pixels and enlarges them. Sure, if one has no editing skills, it can be a convenience. And if one has a large range of light intensity, it might result in better exposure by narrowing the range of light to what is available only in the subject area. But quality takes a hit as the focal length of the lens doesn't change. It is this change in the focal length of a telephoto lens which allows the size of the field of view to be varied as it hits the image sensor. The entire image sensor is still being used, instead of just a portion of it, and thus image quality is maintained. That's the difference between optical (lens based) and digital (camera based) zoom.
You could tweak the picture coming off the camera to white balance better if you were so inclined. There may well be an app for that. Not working with a RAW file, you'll experience a slight loss of image quality when you save again, as jpg compression is not a loseless algorithm. But the image colors would be more accurate and side by side you'd say it was the obviously better picture. RAW files are great because they contain the "raw" image sensor data without any manipulation that cameras apply, such as auto white balancing and jpg compression.
One more for you:
