3. Qg5 wins for White, since Black can't stop 4. Qh6. The best Black can do is 3. ... Qe6 or 3. ... Nd5, but after 4. Qh6 Qxf6 5. exf6 White will inevitably play 6. Qg7# (My computer found a slightly longer delay with 3. Qg5 Bc1, but White still wins without effort).
Why not 2. Bf6 g6?
In that case, it would be more profitable to do 2. Bh6 g6, 3. Bxf8