It is Topic No. 1 in the political world, but the proposed mosque near Ground Zero never came up in discussion when Mayor Bloomberg said yes to an unexpected invitation and played golf yesterday with a vacationing President Obama on Martha's Vineyard.

At least that's what White House spokesman Reid Cherlin would have us believe.

"The president and Mayor Bloomberg took the opportunity to discuss plans for short- and long-term economic growth at a pivotal point in our recovery," Cherlin reported.

That explanation did nothing to quell speculation as to what was really behind the get-together, which was arranged several days ago and marked the first such outing between the two men.

"It's definitely a telling invite," said one Democratic operative.

"Bloomberg can really help Obama fend off the crazy Tea Party types. He's an independent, and he's the most well-known mayor in the country."

The operative added that it couldn't hurt Obama to cozy up to the billionaire mayor, who may still harbor presidential ambitions.

It was only three weeks ago that Bloomberg had breakfast at Gracie Mansion with Vice President Joe Biden.

Joining Obama and Bloomberg at the Vineyard Golf Club were White House trip director Marvin Nicholson and Washington power broker Vernon Jordan.

Obama probably didn't get an upbeat assessment of the economy from the mayor. Just hours before jetting north, Bloomberg, speaking on his weekly radio show on WOR, questioned whether the federal stimulus program was working.

"Our economy is doing well. The rest of the country? I don't know," he said. "The statistics are worrisome about the whole country.

"The stimulus bill, in the end, didn't go to do what the stimulus did back after the Depression in the early '30s. Then, they built schools and bridges. Most of what we have was built then . . . And this Congress did a lot of stuff which was operating and not long-term infrastructure."

david.seifman@nypost.com

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