The reason your variation listings from Amazon were imported as non-variation listings is that Amazon limits our importing ability and does not allow us to capture the variation data. We apologize for any inconvenience. As a workaround, the best way to import variation listings from Amazon is to cancel your connection with Amazon (you can do this from the "Selling > Import from Amazon" page) and downloading your inventory from Amazon into a CSV file, which you can then upload to Bonanza. You will need to format the file with variations to match Bonanza's formatting. It is also best to delete all of the imported listings you have so that you can start clean before doing the CSV import. You can delete listings in bulk from the "Selling > Batch edit items" page.
Above is a link of our sample CSV template. If you have trouble with your file, then you might want to first break the file into 3 items (or something small) and submit the file. That way you can make quick changes until you get the right formula, then apply those changes to the rest of your file. Below are some links that may help.
What type of HTML is allowed at Bonanza --> https://support.bonanza.com/hc/en-us/articles/360001100971
Everything there is to know about a CSV Inventory file --> https://support.bonanza.com/hc/en-us/articles/360000656491
Should you experience issues with your CSV upload, the errors that we mostly see when uploading a CSV file tend to be that users are missing required columns in the file, such as title and category. If a user has the columns "title" and "price" in their file, all of their items must specify a title and price. Every item that is missing a title or price is an error, and after 10 errors, the CSV importer will give up. Another reason for errors is incorrect formatting (presumably rows missing the correct number of delimiters).
Make sure that the categories match the Bonanza category system (Bonanza uses eBay categorization, which is different from Amazon).