Yes, I had a convo ages ago on twitter on how to do this. You just create a separate image with the status bar you want to use on your homescreen and name it WallpaperGradientPortraitBottom@2x~iphone.png and place it in your com.apple.springboard folder of your themes bundle and you should be good to go. It's easier this way because you can change your wallpapers on your SB.
You mean WallpaperGradientPortraitTop@2x~iphone.png right? I didn't remember until you answered my question... but now I remembered seeing these images in a theme.