You don't need to treat a few centimeters as transmission line, but the capacitance can matter though, because it's in the antenna impedance range.
You'll most likely want an inductor to compensate the antenna capacitance. A receiver amplifier doesn't necessary need impedance matching, because noise minimization is the primary objective. If a wide bandwidth requirement adds, a non-resonant active antenna design is suggested. But for small bandwidth, simple LC network impedance matching is the most preferred way.
I agree about extracting the amplifier input impedance from known transistor parameters.