If you add power, you must lower the nose if you wish to maintain your current vertical speed, and your airspeed will increase. In a single-engine aircraft with a low-mounted tail such as the Cessna 172, this occurs because more air is suddenly being pushed over the horizontal stabilizer, which makes it more effective and pitches the nose upwards. (Keep in mind that the tail pushes down.) The exact opposite is true when you reduce power.
In an aircraft where the engines blow air over the wings, an increase in lift will precede an increase in speed, which may cause different behaviors depending on the design of the aircraft. Your pitch attitude will still have to change, not because of the engines pushing air over the tail, but because of the increased forward speed pushing more air over the tail.
I hope I'm not too confusing here.:book::)