There are 2 issues in com_tags concerning meta tags.

1) Author meta tag: created_user_id instead of author name

• Use/Install Joomla Staging plus Test English (GB) Sample Data.
• Set System > Global Configuration > Site > Show Author Meta Tag:YES
• Go to front end > menu All Modules > menu item Popular Tags.
• Click tag "Yellow".
• View HTML page source.
• Actual result (before patch): created_user_id instead of author name:

<meta name="author" content="107" />

• Try also with authors entered in fields Components > Tags > Yellow > Publishing > Author's Alias or Author.

Same result.

• Apply patch.
• Reload HTML page source: Now we see the author name

<meta name="author" content="Super User" />

Or names that you entered in fields Author's Alias or Author.

2) Robots setting ignored

• Use/Install Joomla Staging plus Test English (GB) Sample Data.
• Go to menu manager and set menu filter to "All Front End Views".
• Search for word "tag" and unpublish found 3 com_tags menu items (to be sure that no menu setting will override our robots setting).
• Goto Components > Tags and open tag "Yellow".
• Set field "Robots" to "noindex,follow" and save.
• Go to front end > menu All Modules > menu item Popular Tags.
• Click tag "Yellow".
• View HTML page source.
• Actual result (before patch):

No robots meta tag.

• Apply patch.
• Reload HTML page source: Now we see the robots meta tag

<meta name="robots" content="noindex,follow" />

After patch the bahavior concerning robots meta tag is the same like for a single com_content article. When you publish menu items of com_tags and test several combinations of robots settings you'll see that single tag view inherits settings from menu items as long as you don't override it by a robot setting in tag itself.