Please refer to this Excel spreadsheet with updated ItemType properties for Bridge objects for use with 2021 Release 2 (March 22 Release).
Known limitations in OBM 2021 R2:
1. Steel Tubs, CrossFrames, Stiffeners, Splice Plates, Segmental Bridges will be added in future releases.
2. Publish to iTwin or iModel does not support transfer of Item Types from OpenBridge Modeler.