Generally a "Scene" is an encounter that takes place usually in one location with one or more groups of people. It's defined usually in an adventure as "Scene X". There are not usually 'scenes' for traveling unless something can happen during travel.
There is a really good thread in the Chronicler's Quarter on buffing for scenes ahead of time:
Pre-Buff Thread.
The general consensus is if everyone is assumed to have every scene buff at the start of every scene, it can create imbalance for casters/buffs and that encounters will need to be made harder to account for this.
There are some good GM thoughts on rules of thumb in that thread as to how people handle it. You might chime in there for further insights.
John