Americans considering the treaty route rarely move alone, and the treaty text gives no obvious answer on whether a partner and children ride along or have to qualify on their own terms. Unmarried couples face an extra evidentiary step here that married ones do not.
Yes — your spouse or registered partner and any children under 18 can join you as dependents through the standard family reunification (gezinshereniging) route tied to your DAFT permit, without independently qualifying under the treaty themselves. This tends to move relatively smoothly compared with some other family-reunification cases, since DAFT applications generally get favourable handling from the IND, and that tends to extend to the linked family applications. Your partner gets a residence permit tied to yours and typically free labour market access once they have it, and kids get BRP-registered and enrolled in the local school system like any other resident child. Unmarried partners can also qualify, though you'll need to show a durable relationship — proof of cohabitation or a long-term relationship, similar to what the general partner visa route asks for, not just a declaration. One practical note: because your own DAFT status depends on maintaining "main residence" in the Netherlands, bringing your family and then travelling extensively as a household can raise the same residency-continuity questions for both of you, so it's not purely a formality once everyone's settled here.