Data transfer to iPhone happens in two ways:
a) As a USB device, without iTunes installed on the PC - This shall be monitored and blocked by DLP Endpoint agent
b) via iTunes - In this case the device does not connect as a USB, but rather leverages the application API for data transfer. The same may be monitored/blocked by adding iTunes as a monitored application for Endpoints.
Similarly most Android devices either connect as USB or use the OEM software for data transfer. The approprate softwares may be added as monitored applications.
While it is possible to monitor multiple applications, I would not recommend so because:
a) There will be a performance impact on the endpoint for each additional monitored application
b) It is best to implement a security/compliance solution in a manner that it does not impact end user experience/productivity.