Have you inquired about this on the TeamSite forum?
Importing multiple files from MB to TS is possible in RichMedia UI. Selecting a workarea in RichMedia UI and you can drag and drop the files to LightBox so that the files will be imported to TS workarea.
What is the version of TeamSite and MediaBin?
i saw in the post that below are versions
TS 672 SP2, WFM 1011Unix EnvironmentMediabin 4.6.1
i don't think rich media UI is available in this version
if we make the below attribute to true in constants.asp in mediabin web client folder. Mutltiple file upload applet will be enabled in MB 4.6 web interface
_AppletFileTransfer = False.
This applet is not useful for TS and MB integration. It applies only to MB Web (ASP based) client. And it should be enabled for bulk file/folder uploads in legacy Web client.