Year-end bonuses are up, but don't rely on getting one

What to do with a year-end bonus
What to do with a year-end bonus   

The holiday bonus is back, although workers might find it's not quite the windfall they expect.

According to a new survey from outplacement consulting firm Challenger, Gray & Christmas, 78 percent of businesses will offer a year-end gift or bonus, up from 53 percent who did so last year. It's a reflection of not just profits, but a shrinking talent pool as hiring increases. "The need to keep the talent they already have is undoubtedly a driving factor behind the increased percentage of employers awarding year-end bonuses," said John A. Challenger, chief executive officer, in the news release.

Read MoreStill shopping? Try these last-minute strategies

But don't start planning your spending spree just yet. The firm surveyed just 100 human resources professionals, so it's tough to gauge how this trend will play out on a larger scale.

"I can tell you it's not going to be as great as what happened in 2012," said economist Chris Christopher, director of U.S. and global consumer economics for IHS Global Insight. That year, an unusually high number of companies paid out bonuses, largely due to fiscal cliff fears. This year, there's nothing brewing in the economy that's predictive of a big bump, he said.

Read MoreStore credit cards with the best, and worst, benefits

Holiday bonus
Charles Taylor | Getty Images

Even if you get a bonus, it may not be generous. Half of respondents in the Challenger, Gray & Christmas survey said their companies are doling out cash, gift cards or small gifts valued at less than $100. And of the half that will give out traditional cash bonuses based on performance, 77 percent plan to keep bonuses at the same levels as in 2013. Just 22 percent are offering more generous bonuses.

Wall Street, as usual, is the exception to the rule. The average bonus paid to securities industry employees was $164,530 last year, up 15 percent from the year before, according to the Office of the New York State Comptroller. "That average will likely increase again this year, thanks to a strong stock market," said Challenger.

Read MoreBig changes are coming for credit cards

The uncertainty of bonuses means they're not something that should be factored into your budget, said Gail Cunningham, a spokeswoman for the National Foundation for Credit Counseling. "No one wants to be thrown into the situation of Clark Griswold [in National Lampoon's Christmas Vacation]," she said, "where his boss doesn't come through after he's already signed the contract for the swimming pool."

Although Griswold's boss later reconsiders under, let's say unusual circumstances, bonuses usually aren't up for reassessment. "Live your life on what you can count on," Cunningham said. That way you're at most disappointed, rather than in unexpected debt, if the boss is less generous than expected, or subs cash for a less-flexible reward like retail gift cards or extra vacation time.