Remember, it's a cap gain distribution, not a dividend. And a cap gain distribution is simply the fund giving me back some of the price appreciation. Because I reinvest it back into the fund, I won't really "feel" any richer.
But back to the topic of bunching: I took another look at my spreadsheet and saw that I can go back to bunching my deductions for 2017. The huge increase in my AGI means my deductible med expense will drop by enough to put me under the SD by about $1,000. At 15%, I'll recover about $150 due to the bump-up to the SD this year, and a little extra next year due to the way state tax rebates received in a subsequent year are handled in the determination of MAGI and the ACA subsidy.