This is what I have in my spec file:
added_files = [
( 'myFiles/tests', 'myFiles/tests' )
]
a = Analysis(['main.py'],
pathex=['/Users/me/Documents/MyApp'],
binaries=[('/Users/me/Documents/MyApp/driver/chromedriver','driver')],
datas=added_files,
hiddenimports=['selenium', 'tkinter'],
etc..
This is assuming the original chromedriver binary is inside a folder called driver, and I reference the full path. Does this strategy work for you? If not, what error message are you getting? It might be worth it to try to run pyinstaller without the --onefile to see if the chromedriver is actually included. Let me know!
Jay