The blinds are 300/600 with big blind ante of 600. A player not in the blinds position has only 100 and moves all in.
Can this player win the 600 ante if they win the hand?
This is an expert opinion and not expert answer. While were I am at we have been doing the blind ante in larger NLH games and NLH tournaments this question has not come up with me anyway.
Yes the all in player is in for the ante. Because if the player has been dealt in before, the player has already posted an ante prior which entitles him to hands until he can no longer post an ante.
The ante on the blind is simply a device to prepay antes for the round until the blind reaches you again. It is a really nice thing that saves a lot of time. The point being the player is pre paying the antes for his round, so he is in for the antes because his ante is technically already been paid.
My opinion as a long-time floorman and tournament director:
It depends on how the ante is paid. If each player has to ante 600, and he has only 100 at that point, then the main pot that he can win is 100 from each other player and no more. The rest of the antes and all bets after the antes are on the side.
If it's a game where one player antes for everyone and another player pays that ante, it is assumed that his ante is paid for as well, so he can win all the antes plus 100 from every other player. If he is the player due to pay the table antes, and he has only 100, then he goes all in for the ante and can at best win the 100 back, but no more. If he does win the 100 back, then the next hand someone else pays the full ante and he can win that.