Bonus Skill - How do I get my third bonus skill?
The third bonus skill was a Christmas skill. It disappeared from the store after the holiday (anyone who had purchased it still has it, but the ability to buy it disappeared). It will likely become available again in December, although I expect some other bonus skills will come out before then.
I don't know, I purchased the Christmas skill last year so I don't think I would be able to see if it's back in the store. If you don't see it, then I would guess not! But it came out pretty close to Christmas last year... like mid-December if I remember correctly. Since it's not new anymore - it's already developed and ready to go - I would guess that if they're re-releasing it it would be around December 1st.