Talent of the Telepath & Rattlechains in play

If you have Rattlechains in play, and then you cast Talent of the Telepath and choose another Rattlechains as your selected card, then chosen card is only getting 6 mana instead of the 12 that it should (6 from Talent of the Telepath and 6 from the Rattlechains in play).

Also related to Rattlechains as mentioned in another post, it's only giving 6 mana to the first spirit in hand instead of all of them as stated on the card.