1. For a perfect (ideal) gas, the Mayer relation is $C_P - C_V = R$ and it is independent of temperature.

2. But here the question states:

   • At state $P$: $C_P - C_V = R$
   • At state $Q$: $C_P - C_V = 1.10R$

   Since the difference is not constant, this indicates the gas is not ideal.

3. For a real gas, we use the general thermodynamic relation: $C_P - C_V = -T\frac{\left(\frac{\partial P}{\partial T}\right)_V^2}{\left(\frac{\partial P}{\partial V}\right)_T}$

   This can also be written as $C_P - C_V = TV\frac{\alpha^2}{\kappa_T}$ where $\alpha$ is the coefficient of volume expansion and $\kappa_T$ is the isothermal compressibility.

4. From this general relation, $C_P - C_V$ is generally proportional to temperature (for a given substance/state dependence), so a larger value of $C_P - C_V$ corresponds to a larger temperature.

5. Comparing the two states: $(C_P - C_V)_Q = 1.10R > (C_P - C_V)_P = R$ hence $T_Q > T_P$ or $T_P < T_Q$

6. Therefore, the correct option is: $\boxed{B}$

7. Check the given options:

   • A: $T_P = T_Q$ ❌
   • B: $T_P < T_Q$ ✅
   • C: $T_P = 0.9T_Q$ ❌ (this exact proportionality is not justified)
   • D: $T_P > T_Q$ ❌

So the best conclusion is only $\boxed{T_P < T_Q}$