Recently started using the bulk API and had a similar issue.  For a bulk lead import that's not for the default partition, you also need to specify a static list ID to hold the results of the import (even if the file is updates only).  An URL with query string would be: /bulk/v1/leads.json?format=csv&lookupField=email&partitionName=MyPartition&listId=101   ... View more

Also - you may want to set up the UTM fields in Marketo - we have smart campaigns set up that read off the Google Ad utms. For example, we have UTM_term as a field and the campaign picks up the 'clicks link' add to list/program/nurture if it includes utm_term=google. ... View more