The new feature guide for Dialer Persistent at http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122newft/122t/122t4/ftdperst.htm shows sample configs both with and without a dialer-list/dialer group construction. In the step-by-step section, it demonstrates adding them to the config, but describes the dialer-list as being "...interesting packets that CAN trigger a call...." Further down, in the command reference section, it states that "...to force a dialer interface to be connected at all times...use the dialer persistent command...."
Given that they have samples of both, I'd say no, you don't need the dialer-list/dialer group construction. I'd also suggest dropping a line to bug-doc@cisco.com and letting them know of the ambiguity. That's what they're there for.
