SPF checking works for me and it's not necessary to use cbpolicyd for it. Here's the output of an email from google:
This is on a new install of ZCS 8.0.x and has had no changes made to it's configuration. Are you (the o/p) sure the sending server(s) have SPF records? As far as I know, if they don't you won't see anything.
X-Spam-Status: No, score=-3.037 tagged_above=-10 required=5
tests=[BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1,
FREEMAIL_FROM=0.001, HTML_MESSAGE=0.001, RCVD_IN_DNSWL_LOW=-0.7,
RCVD_IN_MSPIKE_H2=-0.588, SPF_PASS=-0.001] autolearn=ham