Integration with MicroStation (via MicroStation and the i-Model API) is via a plugin for Bentley MicroStation that can write from MicroStation directly to a SYNCHRO Project (SP) file.
There are two versions of plugin: for MicroStation SELECTSeries2 and MicroStation SELECTSeries3. To determine which version of MicroStation is installed go to Help->About within MicroStation.
Once exported, you can import the SYNCHRO Project file in your existing Project using the Importing a SYNCHRO Project features.
Related Topic(s):
Navigator->External Data->SYNCHRO Project