I have an older model cell only Wilson booster and on my second trucker antenna. (the first got ripped apart above the RV, now I run it under the top next to the ladder.)
You have to be sure the booster is in the same range as your phone service. I got mine from ebay for about half price at the time that was $200 instead of $400 or so. I also put in another 12 volt outlet for the system and direct wired the antenna to the rear ladder.
The booster I have is wireless so it amplifies more than one signal in the vehicle. Will also help keep signal longer when traveling in more remote areas between towers. Will not help with no antennas in the area. There is an android app called Antennas that will pick out those that are in your vicinity and my phone will actually display the increase in signal when I look at the settings. I have seen it go from one bar to four with the booster.
All in all a very nice addition to your travel.