By default - organization admins will be able to see all surveys. Normal users will only see the surveys they've created and the surveys that have feedback from the channels they have rights to.
To set a survey as "public" so they will be visible to everyone inside the organizations:
1. Go to the 'Surveys' tab
2. In the surveys list, click the options button on the far right
3. Click 'Make public'
Your survey is now public within your organization.
NOTE: Only the author and admins can edit public surveys.