Spirituality:
1) level of indoctrination, the more "spiritual" the more indoctrinated
2) measurement jws use to judge/rate submissiveness to the org or a potential apostate, usually detected through subtle conversation sprinkled with recently changed doctrine
Jehovahs blessing:
1) an undefined reward that supposedly comes to jws that suffer for the org--it's never really clear what jehovahs blessing really is, but if you give up your career, your home, your money, and your family to pioneer you apparently receive this
2) absolutely nothing