I think that MicroStation data in Oracle or other databases through the MSLINK system has never been officially supported by GDAL. GDAL does not even support the DGN v8 format which was introduced in year 2000 because the format specification is not open. It is hard to believe that this ticket will ever be fixed, especially because is seems that Bentley Geospatial Server V8i is using data from standard Oracle tables which can be accessed through OCI driver.