Not that I know of.
Use a bluetooth adapter like the WiRivo.
You have three bluetooth connections available: Phone, Music, and Intercom. GPS is connected through the Phone channel. If you connect the iPhone to the Music channel, I don't think you could use it as a phone through the intercom. If you connect the iPhone to the GPS, you can use it as a phone, but any music you play on the iPhone will not be in stereo since the Zumo 550 does not support stereo bluetooth. To get full phone capability and stereo music capability, connect the iPhone to the Phone channel, and use a bluetooth Adapter on the stereo output of the Zumo, then play music from the Zumo. The order of priority is addressed in the manual.
A link to the manual is available here
From the Manual:
3.8 Telephone + Stereo (A2DP) + Intercom function
With this combination, the connection to the telephone function ta-
kes priority. Before connecting the devices, please ensure that all three
have been used at least once with INTERPHONE F4.
• During a telephone conversation, interphone conversation
and the playing of music are not permitted.
• During an interphone conversation, you can answer or re-
fuse a telephone call received. To answer, press and release
the MFB button, to refuse press and hold the MFB button for
approximately 4 seconds.
• During an interphone conversation, the playing of music
is not permitted.
• Whilst listening to music on the Stereo A2DP, you can
answer a telephone call received, or enable an interphone
conversation. To answer, press and release the MFB button.
To enable the intercom function, press and hold the MFB
button for approximately 3 seconds. An acoustic sound will
advise you of connection. Conversation in intercom mode is
• To adjust the volume, press the buttons Volume + or Volu-
me -, depending on the desired volume level.