GREP Style Bold Specific Words with ( )

After a \Q *all* GREP codes are disabled, except for the \E one enabling them again. It's not listed in the Online Help at Find/Change text in InDesign but, yes, indeed implemented in the standard GREP package that InDesign uses.

You won't be needing this very much because usually it's easier to escape the few necessary characters "immediately" (that is, if you know what characters to escape), and for a plain text such as this I'd simply use regular Find Text instead of GREP. But the GREP Styles always need GREP, so yeah, @Michel, well spotted.