If you create or link to a Meeting Workspace site from a Microsoft Windows SharePoint Services event, only your name is automatically added to the Attendees list. You have to manually add the other attendees to the list. Whether you and the other attendees automatically get permissions on the workspace after being added to the Attendees list depends on the permission settings used when the workspace was created.

Workspace site uses the same permissions as the parent site

You and other attendees who already have rights to access the parent site will automatically have rights to access the workspace. For this to work, you must enter a valid e-mail address (for example, someone@example.com) or user name (DOMAIName) in the Attendees list.

Attendees who don't have access rights on the parent site must be granted rights there first. Only the Administrator of the parent site can grant those rights.

Workspace site uses unique permissions  <used this option

You and other attendees will automatically get access rights on the workspace if you are added to the Attendees list using a valid e-mail address (for example, someone@example.com) or user name (DOMAIName). As the meeting organizer, you will be assigned to the Administrator site group.