Yes, if you have a 4th generation apple TV within Bluetooth range of your August Smart Lock that is setup to work with HomeKit. You can then use Siri remotely or operate remotely through the August app.
The diagram below explains how the integration works:
If you have a HomeKit-enabled Smart Lock, adding a new Owner and giving them HomeKit access can be done at the same time.
For more information on sharing HomeKit access with other users, check out this article.