Not sure about the merger part but it's certainly not because the price of crude has gone up. A 6-7 dollar hike in the price per barrel of crude should never equal a 50-60 cent per gallon increase to the consumer. Just in my area alone the price at the pump has increased another 15 cents in the last week.
It's gone up a lot more than 6-7 bucks in the last couple of years. Of course, the short term increase you are talking about is due to a lot of things, ranging from an increase in oil prices, to lack of refinery capacity, to higher wages, etc. I doubt that you can ID any mergers that have occurred in the last few weeks that might explain it.
That's OK, nobody else is either, but if it sounds like a slam on GWB, the bots will be all over it like white on rice.