Ok because I do not fully understand from which directory you are calling your scripts, let's make clear we're on the same line here :).
So let's say you have directory C:\wamp\www\x. In x, you have src\autoload.php, i.e. C:\wamp\www\x\src\autoload.php. So when you are now inside directory x in your terminal, calling phpunit --bootstrap src/autoload.php tests/MoneyTest directs to folder src in your current folder, and to autoload.php in the src folder. Is this what you are trying, and is this where you are getting your "autoload.php cannot be opened" message?