Bounce cards can only be played after blocks are declined.
But, under the new D action rules, if my prey bounces a Spirit Marionette
bleed, he is still a target of the (D) action because I'm going to tap his
minion. Correct?
If that's correct, can he now attempt to block it again, if the new target
of the bleed doesn't attempt to block?
No. Spirit Marionette only targets the Methuselah being bled.
http://groups.google.com/group/rec.games.trading-cards.jyhad/msg/7ab4c9244a2c1592
Supposing that your prey is a target of the action (which isn't sure),
I'd say : when the target changes, everyone one gets a new opportunity
to block. So there goes your prey's new block window.
(next blocker would be the target of the bleed, and then, clockwise).