your structure doesn't make sense, the foreign key link is not needed in both tables.
manage relational table is used to manage a third linking table to create a many to many relationship, i.e. where an enquiry could realte to many properties.
otherwise, if using a one to many relationship, where an equerry could realte to only one property, you would not need the property ID in the enquiry table, but keep the enquiries_id column in the property table.
use 2 inserts the first to save the to the enquiries table, in the insert, you can set the session name to save the ID to.
In the second insert to the property_enquiries use the session binding for the enquiries column.