You cannot see the transfer function of a switched-capacitor filter using AC analysis. The switches do not switch in an AC analysis because it first linearizes the circuit about the DC operating point. The filter should work properly in transient analysis, but it is difficult to see the bandpass nature.
Consider using the PSS/PAC analyses of SpectreRF. Read "Simulating switched-capacitor filters with SpectreRF" for a description of how to do this. It can be found at
http://www.designers-guide.com/Analysis/.
-Ken