Sometimes it is asserted that the phrase we were powerless is written in the past tense, so it is no longer true. The reason the phrase is in the past tense is that the past tense is consistent with the verb in the main clause, namely admitted. 'We admit we are powerless' thus becomes 'We admitted we were powerless'. A statement in the past about a condition in the past cannot indicate whether that condition in the future will be persist or pass, however.
However, the question is relevant and interesting. To answer the question of whether we remain powerless, we have to understand what an admission of powerlessness means. If one examines closely the material on Step One in the book Alcoholics Anonymous, it is clear that being powerless means (a) not being able to stay away from the first drink through common sense prevailing over irrational impulses and (b) not being able to stop at a few drinks when we start.
Are these true even after one has recovered? The second element is still true: the experience of people who recover from alcoholism but later drift and lapse is that recovering through the steps does not alter the body such that drinking does not induce an insatiable craving for more.
The first element is more complex. If we successfully stay away from alcohol for years, it seems, on the face of it, that we are no longer powerless: if we were, why are we sober? It is true that power has been acquired, but there are two features of that power that are of note. Firstly, the power does not consist in common sense prevailing over irrational impulses. Although on occasion this is the form it will appear to take, my experience at least is not that reason is prevailing but that spirit is prevailing, in the same way that when I stand back from the edge of a tall building it is instinct that governs me, not an analysis of mechanics and anatomy suggesting that if I fall my internal organs will sustain irreparable damage. It is not intellect that prevails but instinct. The same is true when I 'recoil from [a drink] as from a hot flame'. Secondly, the power given is contingent (on the maintenance of a spiritual way of life) and does not become inherent. I, myself, am powerless, but I am not only myself any more: I am part of a greater whole, and it is that assimilation that confers power.
So, are we still powerless, years later? More yes than no.