There are plenty of reasons to fly long range bomber flights over neutral territory but close to national boundaries. Those reasons are difficult to fathom if you've never been part of "the game" and just read snippets of news articles. Here are a few things to ponder.
The purpose of long range bomber flights isn't to incite anyone to war but to learn something about the preparations and capabilities of potential enemies. When you fly those flights, you create a lot of activity that can be invaluable to your military planners.
Once you leave your own national borders many things begin to happen. Radars light up, command and control units come awake, communications networks suddenly get busy, and finally, defensive fighter units take to the skies. All that activity can be detected and later analyzed. While those bombers are in the sky, there are thousands of people on the ground from many countries that spring into action. Meanwhile, thousands of your own people are listening, watching, recording and reacting to those events as they unfold. When done, you've learned a lot about the defensive posture of other nations. You know their manning capabilities, you know how long it took them to react, you know how long you were tracked and when and where that tracking began and ended. You know the types of equipment used to detect and track you and the types of defensive weapons employed to intercept you. Then you probe another route to determine if/when/how you were detected. You do it again and again at various altitudes and speeds and with different airframes until you learn the most probable routes to fly should the need ever arise to go to war.
Then the analysts back home go to work after the fact. Did the defenses of Country X respond quickly enough to defend against our flights? Did Country Y make it almost impossible to cross near their territory without being detected? Did Country Z put up a defensive force in sufficient numbers skilled enough to ensure we couldn't fly near their country? Which fighters were used and from where? What was their response time? What equipment did the intercepting fighters turn on when near us? What do we need to do to defeat that equipment? What frequencies did the fighters use for command and control and how can we possibly jam those frequencies in time of war? The questions are almost never-ending. Every possible or potential event is envisioned by your war planners and you go to work devising preparations to defeat each and every possible scenario that might be thrown at you.
And then you do it again. No, those Russian bombers were not just posturing. They were not trying to goad us into attacking them. They were not trying to start a war. They were simply getting educated.