I haven't seen either drop from any enemy (and I have been keeping track) so I would assume either from the Moogle shop, the Flick Rush Shop (where you use your gained medals) or Link Portals.

I don't know anywhere else you can get materials (except chests) so try those, bearing in mind the flick rush shop gets a bigger inventory the higher your flick rush rank is (at least I think it does).

Wild fantasy is from Sora's side special portals in The world that never was. I'm not sure about the malleable fantasy, but I will post if I find the location.

I don't know about wild fantasy but I know where you can find at least one malleable fantasy. Goto Prankster Pardise ( Pincocho's world) as Sora and goto the ferris wheel and check each one of those seats to find this chest with malleable fantasy also this other chest.

i found a malleable fantasy in La Cite des Cloches with sora in a special 1 star portal.

I found a Malleable Fantasy in a portal in traverse town

Malleable fantasy is in a special portal....i think the portal is located in 5th district traverse town