I'm still working on getting my AA set up to support my cash flow, but I am targeting (and very close to) a 50/45/5. Equities are throwing off about 3% (15k per million of portfolio with this AA). I like long muni bonds, and that is where most of my bond allocation is. Mine is throwing of 5.7% fed/state/amt tax free. Using a more conservative 5% muni interest rate, in a one million port, this would throw off 22.5k. Then there's the 5% in cash in a state tax-free MM, throwing off about 1% or 0.5k per million of port. That's 38k total, 3.8% WR. And, there is not likely to be much fed or state tax on that dividend income unless you have zero deductions.
For me and DW, the 5% cash will represent 2 solid years of spending, 3 years of more conservative spending, or almost 4 years on the barebones plan. For us, it is looking like we will have a spend/WR rate of about 3.2-3.4% so the rest (considering a 3.8% cash throw-off rate) will go back into rebalancing. We also have sufficient deductions (estimated - including personal exemptions, charitable giving, healthcare, and property tax) that fed, state, and AMT will be tiny if any.
All of this said, almost all of my retirement funds are in taxable accounts because I was only eligible to participate in megacorps 401k for a few years for various reasons. This plan may not be the most appropriate for someone organizing cash flow from tax advantaged accounts.
My two cents, FWIW.
R