Not quite.

With Total Rewards you earn 1 Reward Credit ( = 1c in comps) for every $10 bet at video poker. So a 5x multiplier increases your return to 5c per $10 wagered or 0.5%. Given the crappiest payables easily have a return of less than 97% you'd need a 30x multiplier to approach a breakeven expectation..
I would venture to say that there are very few machines in Caesars properties where a 5x multiplier would result in a positive expectation.

Harrah's New Orleans often has multiplier days where you swipe your card for a mystery multiplier of up to 100x but I have yet to get a multiplier higher than 9x (which is actually the minimum awarded for 7Stars cardholders). Even then the higher multiplier applies only to slots and video poker is limited to 3x regardless of the level of slots multiplier won