My wife is having the exact same problem, though she completed her minimum spend longer ago than anyone else who has posted here so far--back in early April. After no bonus points posted for several months, we contacted Amex about three weeks ago, at which point the agent confirmed that my wife met the spend requirement and never previously had the card. I've checked back twice since then, but her points still haven't posted and the inquiry is still pending.
The last agent I chatted with tried to tell me that her federal income tax charges didn't count toward the spend requirement, but then the list of exclusions he copied and pasted only mentioned "federal excise tax fees," which clearly was inapplicable. When I asked him where federal income taxes were excluded, he simply demurred and said to check back on the open case in a few days.
Anyone have any ideas how to speed this up?