Is it correct to say:
even if only James Bond will benefit from...
or
even if only James Bond benefits from...
Even if is never followed by a future tense. The correct alternative is:
Even if only James Bond benefits from...
I disagree with the (currently) accepted answer. I see nothing wrong with...
Even if only you will benefit, it's worth doing.
In defiance of pedants everywhere, I deny that there's any significant nuance differentiating...
Even if only you benefit, it will be worth doing.
Even if only you benefit, it would be worth doing.
Even if only you will benefit, it's worth doing.
Even if only you will benefit, it'll be worth doing.
Even if only you would benefit, it's worth doing.
Even if only you would benefit, it'll be worth doing.
etc., etc.
...and I certainly see no point in debarring any combination on the grounds that it's somehow "not grammatical". The fact of the matter is all these variations occur, and it would be unlikely even for the speaker to choose one over another to convey some subtle shade of meaning. The possibility of his audience actually apprehending any such subtle distinction is effectively zero.
Hypothetical clauses that are headed by if (including even if) may only use the modal auxiliary verb will (or won't) in its Deontic sense of 'intend, be willing', and not in its Epistemic sense of predicted necessity.
Since there is no future tense in English, futurity is inferred rather than marked per se. Common constructions include be going to, the present tense (as here), or some modal auxiliary (will, may, can, should, must, etc).