To add company gifts to a TeamRaiser once org gifts are enabled:
  1. Create an organization or be prepared to use an existing one.
  2. Search for the TeamRaiser and select manage under actions. 
  3. Select the Event Gifts tab.
  4. Select Record Event Donation under Related Actions.
  5. Select Search for Existing Organization and enter the name.  
  6. Choose to either create a new contact or select an existing one.
  7. Once completed configure the gift with the desired options.
  8. Select Process or if you have multiple choose to Process and Another.

The gift will now be connected to the company.  If you do not have org gifts enabled then follow this process instead: guide.