See instructions with a bit more elaboration at Bonjour Simplified
That being said, the “DEVONthink Manual” has three numbered steps.
A common error is turning “on” Bonjour on more than device on the network. Pick you MacBook or your iPad as THE single machine to “accept incoming”. Probably that should be the Macbook.
Bonjour is not related to local sync store, which is something different. Where in the Manual does it suggest to use Bonjour to setup a local sync store?