Looking over my log, I did 225x2 with a close grip on May 18 and 225x3 with ring fingers on ring on July 13 (missing 4th rep), both sets touch and go. So if there is a strength increase with a wider grip, it's marginal at best in my opinion.
I feel that I have problems getting tight and getting power behind the bar with a wider grip. A closer grip is just how I'm used to benching.
Ever since I started pausing my benches, the sticking point became near lockout lol, so I'm not sure how much wide grip work would help with that. Might work some in here and there, but I'm doing reverse-grip benches for a supplemental lift right now.