Usually with the catnap the idea is to let the LO have a 30/45 minute nap, then wake them and do bath and some low key A time. After that you would give the final bottle and put LO down for the night. One thing I did with my DD until she was about 5 months old was to give her a cluster feed in the evening. She was still only having 5 bottles per day, they were just spaced a bit closer in the evening. It looked like this: 7am, 10:30am, 2:00pm, 5:00pm, 7:00pm.
Have you tried giving him more A time to see if he'll take longer naps? The 45 minute nap can mean either UT or OT. However, it looks like his first A time is only 1hr 20min, so I'm guessing he could handle a bit more. You could try adding an extra 10/15 minutes to see if that helps any (it may take a few days before you see results since his body will need to adjust).