local administrator does not have permissions to create database in db2
I had some chats with IBM and the issue is kind of simple. The db2 service is running as a local account (db2admin) just as a default installation would do. My account is a domain account and is in the local administrator group. The local account is not able to verify my domain account and therefore I am denied admin permission.
Solutions:

use a local account for connecting to the database
run db2 service under the local system account
run db2 service under domain account

I changed the setup to local system account. Waiting on IBM for letting me know what the security impact (risk) is.