Hello @Joe_Chance and welcome to the community! Thank you very much for your feedback, and allow me to help you with your question. The most likely reason why your Slack integration is connecting to the wrong account and not showing your company workspace projects is that you have two separate Asana accounts. Ideally, one should use a single Asana account with access to multiple workspaces/organizations, rather than maintaining separate accounts.
To fix this, you may need to re-authenticate Asana for Slack integration using your company account. In Slack, open the Asana app, go to the Home tab, and disconnect from Asana. Then, click Connect again, sign in, and choose the correct Asana account and your company workspace. Make sure you also log out of your personal Asana account, so that it will be your company account that it will connected to Slack.
Let us know if this works, Joe. If not, you can reach our support team directly by following the steps in this guide, so they can check the account link on the backend: How to contact our Support Team Thank you very much and enjoy your Asana experience! 
