IamSam &
ALB68 - Actually, in the version I posted earlier, I started with the PSD file graciously posted by Colleague. Then, I did use the distortion correction (under Lens Corrections) in an ACR adjustment layer, but, because there was what is called, "moustache distortion", in addition to simple barrel, to get all the reindeer perfectly straight, I followed that with a pass through the new "Adaptive Wide Angle" filter. It was only after I was done that I looked down at the layers already in "Colleague's" PSD file and saw that he also apparently applied the lens correction filter.
Three geometric corrections in sequence was just too much for me because doing each one slowly saps the detail out of an image at the pixel level.
So, because I also wanted to show the OP how an absolutely plain background looks, for the version below, I started with the OP's original (instead of "Colleague's" PSD file) and only needed to use one pass through the Adaptive WA filter. It just about completely corrected all the distortion in that one pass and preserved the sharpness in the original to a much greater extent.
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@OP - IMHO, the reindeer wallpaper background, while cute & certainly in the Christmas spirit, is much too busy from a photographic POV. It just screams, "snapshot". If you really want to use such a background, at minimum, always sit your subjects well out from the wall so that the subjects will be sharp, but the wall will be blurred from depth-of-field effects. Of course, the other option is to use a less busy background.
For demo purposes, attached below is the extreme opposite end of the spectrum with respect to visual clutter: a featureless, plain gray background. Personally, I would have gone with something in-between with respect to visual complexity, say, drapes, an very out-of-focus xmas tree, etc., but wanted you to see what a simpler background might look like.
Cheers,
Tom M
PS - Pls. ignore the lousy masking job. I didn't feel like spending any significant amount of time on it since this is only an example / demo.