I fly out of PVD and have two Southwest CC's. If you accumulate 110,000 points in the same year, you can qualify for companion pass and bring a companion for free every time you fly for the remainder of the year and the full year following. Right now the personal cards come with a 50,000 point bonus and the business card comes with a 60,000 bonus. So essentially you could apply for one personal and one business and have 110,000 points for companion pass! Also, the points are really easy to use. I love Southwest and my companion pass!
JetBlue doesn't really have enough time options out of PVD for me to consider the card. I believe only two flights a day. Boston has more though. Jetblue card may be an option for you.