Session/Redis question

If I'm using redis for sessions and I store some session data in variables for 'user' (active user data) and 'business' (active business) and then I get those session variables with:

$session->get('user');
$session->get('business');

Is that making two calls for the redis server?

Am I better off doing:

$data = $session->get();

$data['user'];
$data['business'];

Is that one call?

I'm running my application on the Google Cloud. I'm obviously trying to reduce calls to the redis server and can't see those calls like database calls in the debug bar. That would be sweet if I could... but not necessary if I knew what is happening.

Bonus question, the session docs mention data will be stored in $_SESSION superglobal. Is that true for redis?

Thanks in advance!