Doing Unlock Your Glutes workouts twice per week is enough to see results in a 30-day period. Whether you do the BW only programs, mix BW with Gym or only do Gym programs, twice per week is the recommendation. This way you have time to exercise the upper body and add in some cardiovascular days.
Of course, if you're highly motivated and want more/faster results, you could add a third day per week and follow a Mon-Wed-Fri or Tu-Th-Sa approach. Just be sure to rotate through the programs, if you're really sore or tender in the glutes, listen to your body and take days off when needed.
Like any specific program, all of these exercises target the glutes while also hitting the leg and core muscles. You will notice a positive effect all over the body but really see and feel a difference in your back side. As far as progressions, you wouldn't increase frequency, you would only increase time under tension on timed exercises OR increase reps OR increase sets as you advance.
I would MAX OUT at 3-days per week to ensure you don't over train this area. We wish you well with your glute training and thank you!