Summary: iPhone does not currently sync directly to Oracle Calendar. There are a few ways to transfer your Oracle Calendar data to your iPhone.

The easiest way to view your Oracle Calendar agenda is to connect via Safari on your iPhone.
You may also export your Oracle Calendar agenda and import it into Outlook (Windows) or iCal (Apple). This is a manual method.
Windows users may use Oracle Connector. The Oracle Connector for Outlook is a plugin for Microsoft Outlook. When installed into an Outlook profile, Oracle Calendar users may use Outlook's unified environment for email and calendaring.
Download the software and install on your PC. Use the settings below to configure Oracle Connector.
Synthesis AG makes an iPhone App that syncs with Oracle Calendar. The App is $14.99 and syncs directly into its own calendar, not into the built in calendar. However, you can sync while on the go and make sure you have the latest information. OIT does not endorse or offer technical support this application, but it is one of the better options currently available.