Johnson did not enjoy a particularly good 2016 season, but few Rams did. The team thought enough of him last offseason to place the franchise tag on him and let Janoris Jenkins leave as a free agent for the Giants. It's pretty clear he's not returning to the Rams next season.
An undrafted rookie out of Central Florida in 2013, Bouye enjoyed his finest season and was the Texans' best CB in 2016. It's highly doubtful they will let him leave and he's said publicly he wants to return.
The Patriots will have around $60 million to spend under the salary cap and generally don't let good young players get away.