As part of this Multiclass feat it tells me to:
Choose a warlock pact. You gain the pact's at-will power as an encounter power, and you can pursue the warlock paragon path based on that pact.
Now according to the warlock features:
Pact boon: Each pact includes a pact boon...
Now I understand that pact boon activates mainly when you have a warlock curse on an enemy, but nonetheless do you still have a pact boon because of this multiclassing feat?