Thanks for posting it here so that others could consume.
Not sure what the vendor needs to go through in order to complete a bid. Usually, we could create shots on
Shots entity page with metadata such as shot names, frame range, description etc filled. You could then add custom bidding fields the vendors need to fill in. Export them as a CSV and send the csv as a format to Vendor to bid on.
For the complexity or reference media, we will upload them as versions onto Shotgun and make some notes on these versions. Gather these versions in a playlist and share it with both vendors via Client Review Site. The vendor then could review these media with annotated notes outside your Shotgun site ( no need to have a Shotgun user on your site at this stage).
The vendors could add their bidding information onto the csv excel sheet while reviewing the reference media, and then send back these csv files for review. Once bidding approved, you could use the latest csv file to import these bidding data onto your Shots page directly.
To answer your question directly, you could use the exporter to export the notes you add to Shots, but it’s not supported to export annotated images attached to notes.
Hope I made myself clear here. Let us know if anything else.