I posted last summer on Abstract Tactics, and I'm going to revisit that theme again. I know I'm a voice crying out in the wilderness on this, but tactics are orthogonal to use of miniatures - you can use tactics without using minis. In fact, I never use minis, yet combat in my games is full of tactical choices.
Tactics is all about maneuvering for advantage. Whether you are in air combat trying to get on the bad guy's six, or a cowboy flanking the rustlers' camp to get a better shot, or a detective using a dumpster for cover in a back alley, whenever you maneuver to get an advantage, you are using tactics.
Do you need to know the terrain? That's not necessary, though it helps. If you know there is a hill to the left of the rustlers' camp, you can use it to shoot down on them from a higher position - almost always a plus - but you don't need it. You can just say "I'd like to maneuver to get a good shot at them from above and to the side. Is that possible?" GM says yes or no. You didn't know the terrain, but you used it to your advantage.
Do you need to know where your buddy is while you are doing your thing? No, you don't. The enemy? Well, the ones you are focusing on, yes, but the others? No, you don't. In fact in real life you almost never do. In combat, people focus on what is immediately around them. If your buddy is right there with you, you know where he is. If not, you should only have a vague idea. Read some real-life stories of air combat, as I did while researching my air combat games. The pilot will almost always say something on the lines of "When I looked around after I shot him down, I was surprised to find the skies which were so full of planes were empty." After a dogfight, they have to 're-acquire' the situation because they were focusing so much on their immediate situation. This is universal throughout any kind of combat. You focus on the immediate situation and pay no attention to the large picture. With minis, the large picture is always right there, staring you in the face.
Using abstract tactics,you are concerned with your relation to the particular element of the enemy you are fighting. All you need to know is where you are in relation to the target, and what your advantage is. For cover? What do you need to know? How much of an advantage does it give you. You say something like "I dive for the best available cover". The GM says "You get a cover bonus of X." That's all. Is it a bamboo thicket? A low stone wall? A doorway? It doesn't matter. That's description, and varies according to taste and the terrain encountered. What matters is the actual advantage gained.
These things don't need to be codified into the rules, though it helps if they are. What matters is that there is no hard-coded linkage to exact distances, topography, or line-of-sight. If these things are kept relative, then you can use minis or abstract tactics as you wish.