Which version of this sentence is correct?

With how you have written the sentence the second one is correct. A native speaker would not use 'streamline' in that context. By saying 'for a...' you are describing the software after it has been streamlined, not the actual process of streamlining itself.

If you want to use the present tense of the verb 'streamline' you would use 'to...' instead of 'for a...' and the sentence would end like this-

Grant special permissions to your employees to use different features of this program to streamline the workflow.