We did same thing last year and took the bus to AK about an hour before our ADR at Boma, took bus to AKL from AK, and got there a half hour early for our ADR - looked around the gift shop for a bit, then went to Boma and actually got seated early since we were already there. Enjoy, it's wonderful! When we were done, we wanted to go to DTD, so we took the bus from AKL direct to DTD.