The little I know about telephones, and it's little, is they require a low impedance to signal the switching system to recognize off hook condition. In your circuit, you have a resistor, a capacitor and a transformer all in series, I do not think it's ever going to see that low impedance situation, and may in fact be able to ring when your circuit is powered. I think the resistor is allowing your circuit to pull the line to the required, low impedance (improperly).