I would love for each team to be granted those extra practices. But I'd like to see them with an option to add them on to the Spring if they didn't make a bowl.
So if you make a bowl, then yes you get to use those 15 practices to prepare for a bowl.
If you didn't, then you could start practicing in February, and get 30 practices in the Spring. I don't see the point in trying to say "you didn't make a bowl, but keep practicing while everyone else is playing."
If you are us, then think about what that would have done for us this year? We didn't make a bowl last year. So what if we had 15 more practices with this makeshift offensive line in Spring? 15 more practices with Hurd, Malone? Might have made a difference.
Just a suggestion. Make a bowl = 15 more practices in December. Don't? 15 more practices in Spring. That way the teams who need it the most for the upcoming year get the practices, and the teams that are riding success get the help for the bowl game.