You know, this bothered me too.

RMEF does a lot of good habitat conservation work, and the OP was simply inviting people to a fun evening at a banquet.

But since the immediate negative response hijacked that invitation, and the question was asked, I went surfing to see what articles were out there saying any such thing.

I do remember that RMEF tried to stay neutral "officially" at first, but not that they endorsed introducing wolves into the Yellowstone ecosystem. I went looking for any indications of endorsement, and instead found references to supporting research that was clearly intended to show the impact of predation of elk calves as below.

"Funding research: Rocky Mountain Elk Foundation contributes to wildlife research

By ROB CHANEY – Ravalli Republic
Over the past decade, the Rocky Mountain Elk Foundation has contributed $400,000 to study wolves.
In addition to this spring’s $51,000 donation to U.S. Wildlife Services for radio collars and depredation kills in Montana, the foundation contributed $41,600 to study elk calf mortality in the Bitterroot Valley in 2012. The Missoula-based organization has underwritten a wolf predation study in Idaho’s Clearwater River Basin in 2007, elk calf recruitment measurements in Idaho wolf-reintroduction areas in 2003, predator-prey relationships in Wisconsin in 2003, and the impact of grizzly bears and wolves on elk in Wyoming in 1999." There is more....

And most recently such headlines as "RMEF Supports Delisting of Wolves in Lower 48 States June 07, 2013".

And "Family pulls award over Rocky Mountain Elk Foundation's wolf policy
• By ROB CHANEY of the Missoulian
• Jul 19, 2012

The Rocky Mountain Elk Foundation has removed all references to its Olaus Murie conservation award after the researcher’s family objected to the group’s policy on wolves.

In a letter to RMEF President David Allen, Olaus Murie’s son, Donald Murie, said the organization’s “all-out war against wolves” is “anathema to the entire Murie family.”

“We must regretfully demand that unless you have a major change in policy regarding wolves that you cancel the Olaus Murie Award,” Donald Murie wrote. “The Murie name must never be associated with the unscientific and inhumane practices you are advancing.”

The Missoula-based RMEF has filed amicus briefs in federal lawsuits supporting the removal of Rocky Mountain gray wolves from Endangered Species Act protection. In March, it donated $50,000 to the Montana Department of Fish, Wildlife and Parks to fund contracts with federal Wildlife Services for wolf-killing activity." There is more discussion in this article as well.

None of this looks like endorsement of introduction of wolves.