I don't think I'd call poker strategic OR tactical. From what little I know of the game, it's mostly about: understanding the probabilities associated with your hand; inferring from your opponent's actions the probabilities associated with their hands; understanding how to incorporate those probability estimates into your betting strategy; and recognizing and exploiting the misplays of weaker players. None of that really fits into what I think of as "strategy" or "tactics" in a card or board game.
The only one of those four things I wouldn't label as strategic is the last one. I think of strategy as meaning, you have to use intelligence/creativity/reasoning to make your decisions, but not in a way that can be calculated with any sort of precision. Usually that manifests itself as long-term planning, but I don't think all strategy has to be long-term planning. Dominion is a strategic game because you can't possibly calculate exactly what cards to get at what times; you just have to use your strategic intuition to figure out what kind of deck you want to build, and then how to go about building that deck. Chess I would say is not a very strategic game (except at very high levels of play), because it tends to be decided by who makes the first computational error, even though the outcomes of that move could have been calculated in advance.
So with that in mind, poker is certainly a strategic game. You have to develop an intuition as to the probability of certain hands winning, based on the information that's available to you, and deducing what hands your opponent(s) are likely to have based on their bets. You can't possibly calculate those probabilities on the spot.
But even if that doesn't count as strategy, there is still a reasonable amount of strategy in deciding when to bet and how much. It's not always about knowing how likely your hand is to win, and it's not always about bluffing. It can also be about forcing your opponent(s) into bad positions. You can imagine on the flop, you have an overpair and your opponent may have a flush draw or open-ended straight draw. You know that there's a good chance you will have to fold if the opponent connects the flush or straight on the turn, so you make a big raise so that it is no longer profitable for your opponent to see the next card. That is, you decide your hand is a lot stronger (relative to your opponent's) without knowing what the next card is than it is with the knowledge of the next card, so even though an overpair may not be super strong in general, you can decide that betting big is the best move, not as a bluff, but because if your opponent plays rationally he will have to fold since the strength of his hand heavily depends on the turn (and if he plays irrationally, even better! (on average)). I think that sort of reasoning has to be classified as strategy, I don't know what else it would be.
