My first 135 company was in 2007 and the Captains had company phones for a while. During a cost cutting binge, it was decided that the phones would stay with the airplane. Cost cutting didn't work and that company went bankrupt.
After a stint at the airlines, I got back in the 91/135 world and the company paid $35 a month in cash with no expense report needed. The principal on my plane decided to switch management companies and I went with the plane rather than lose my job. New company paid $34 a month, but required an expense report for each one with a cell phone bill attached.
A year ago, I got back on with the $35 a month company, but since my principal had historically paid for the full bill, it was decided that he would continue to do so. I split my family plan in half and get $72 now.