This works:

restart;
with(Units:-Standard):

R1 := 18.2*10^3*Unit('Omega');

R2 := 10^3*Unit('Omega');
C1 := 470*10^(-12)*Unit('F');
C2 := 4.7*10^(-9)*Unit('F');
wo := 1/sqrt(R1*R2*C1*C2);

Q := wo*R1*R2*C2/(R1+R2);
H := s -> wo^2/(s^2+wo*s/Q+wo^2);

with(DynamicSystems):

# the trick is to specify the unit of the complex 's' parameter, which is in hertz

sys := TransferFunction(H(s*Unit('Hz'))):

BodePlot(sys, hertz = true, output = dualaxis);