If the query if resolving correctly (which it sounds like it is), then yes, it should absolutely work. If the machines are not picking up on the policy even though you see that machine was added to the task, then it sounds like a policy problem, not an LDAP problem.
You can verify that by creating another task, add one of the machines manually (without a query), config the deployment method and start the task. If it still says nothing to install, then you have a policy (scheduler?) problem.
My apologies ... I should have stated that if I drag the Macintosh device from the Network View into the Scheduled Task to directly target the Mac inside the Console, the software packages deploys successfully. However, if I use an AD group containing the Macintosh device, the status is always 'Waiting'.
Futhermore, the LDAP object name of the Mac is displyed correctly in the Scheduled Task. BTW: did you need to modify a setting (similar to DisableLDAPGroupEnumeration=0 for Windows agent) on your Mac agents to perform LDAP deployments at your site?
I've never use an LDAP target, but I would think that as long as the machine(s) resolve from your query, it should work.