If you have not already added your last name and company name to your account, log in and click on Settings select Accounts to do so.
Once you have done that, go to Greetings and select Greeting Summary. Under the Smart Greeting heading, click Edit Smart Greeting and from the drop down menu, select the greeting that includes your company name. You can either request to have your last name AND company name recorded, last name only, or just your company name. Click Save and the request will automatically be submitted. ETA is 7 days.