I looked further at the source where you found the land records for William Bennett Bush in 1837. There were several more publicland grants for him in January of 1837. I also found one in the same township and section for George WASHINGTON Bush dated 1/20/1837. I thoughtthis might beWilliam's brother George. They served together in the Missouri Mounted Rangers in 1814. George reportedly drowned as a young man and I could find no census data for him in Missouri.
OR it may be for William Bush's son whose name was George W. Bush. Most likely!