ST bonnets are the same as facelift bonnets, so they have a small protruding lip on the front to match up with the grill. If you really wanna go down that route, you`re better off buying the whole front end of an ST or mixing the ST bonnet with all facelift parts!
But to answer your question: No, the ST bonnet probably wouldn't look/fit right with a pre-facelift front end!