There should be custom variables available at the company level. Furthermore, they should be accessible at the contact level when the Company Object feature is enabled.

In my scenario, I'm using the company field to keep track of the contractor that handles things for that contact.

I'd like to send a birthday reminder to the sub-account owner and the 3rd party (contractor) that does work for the contact.

I'd like to be able to extend an automation to do this using the company's (contractor) email address to send an email to them (i.e {{ contact.company.email }} ).