Matcha tea chocolate ganache
If the matcha powder has been adequately mixed/stirred in, it should pass through the strainer - on the other hand, if straining/filtering is not in the source recipe, perhaps you should concentrate on mixing throughly so that there are no lumps, and not strain.
As an additional possibility for weak flavor:
I'm always willing to guess (when things don't seem to come out right, especially)  that at some point in the passage of any recipe involving teaspoons and Tablespoons some transcriber might have misinterpreted some prior writer's Tablespoon (T, Ts, Tbs, 15 ml) as a teaspoon (t, ts, tsp, 5 ml) or vice versa.