The flash plugin you have installed is the Linux one. The Safari browser you are running is inside of a windows-look-alike environment bubble, and would need a windows version of the flash plugin installed inside the same environment. I don't think Flash under WINE will help you much with Safari. It is listed with "Bronze" level support on the WineHQ site but the install needs a work-around, only the Opera plugin part actually works, and the various issues seem to be legion.
I would suggest that if so desperately need to run Safari for some reason (testing for example), you should do it inside a virtual machine running Windows using VirtualBox. This will provide you with a clean real Windows environment and allow you to run things like plugins. Safari under WINE might run as a browser but it will never be a fair way to evaluate it's functionality or test sites with it.