Just to be sure since I may have not been very clear in my initial response, did you read this part of the readme file?
FTP & Bulk Uploads:
If you plan to allow some of your users to upload files via FTP, you will first need to make sure that your 'FTP User Folder Path' setting (listed under the 'Modify Settings' link under your 'vBa Gallery' options in your Admin CP) is set to the full path to your '/gallery/users' folder.
You will then need to create a new folder under your '/gallery/users' directory and name it according to that user's userid (so if the user's userid was 5, you would simple create a new folder called 5 under your '/gallery/users' directory.
Lastly, you will need to create a new FTP account on your server for that user and make sure they have access to the newly created folder to upload their files to.
Once you have done that and uploaded the files into the proper folder, you just go to upload an image as you would normally, but instead of selecting an image to upload you just check the box near the bottom that says "Upload images directly from the server".