In the DS9 episode "The Jem'Hadar," Eris the Vorta has telekinetic powers. Later, throughout the Dominion War, no other Vorta have telekinetic powers. Do they just never use them, or was Eris the only one who had them, or what?
I think the official explanation is that this was not a trait shared by all Vorta. The first Vorta that they encounter is unusual in having that capability. A more thorough (including out of universe details) description is given at memory alpha:
Only one Vorta was demonstrated using telekinesis: Eris. As the DS9 writing staff put more thought into the Vorta following their initial appearance in "The Jem'Hadar", telekinesis was discarded and deemed a misstep that the writing team hoped viewers would forget. (Star Trek: Deep Space Nine Companion, p. 155) Ronald D. Moore stated, "Our internal rationale has been that Eris was given this ability for a specific purpose by the Founders (and maybe several other Vorta along with her) and that it is not a normal part of the Vorta 'recipe' in the Dominion." (AOL chat, 1998)
Its obvious the writers simply decided to drop this ability cause it made them to powerful negating the jem hadars purpouse