Energy consumption and the performance of a vacuum cleaner is provided for dry corded vacuum cleaners, however the most popular vacuum is a cordless which don’t have energy label standards set for them, likewise wet and dry or shampoo cleaners are not subject to energy rating.
The energy label is a great idea as it should give you an unbiased and independent assessment of the performance of the cleaner set to a common standard. In truth the amount of energy a vacuum cleaner would use at home is not significant, but you do also get ratings for how effective the cleaner is at cleaning carpets, hard floors and the rating for emissions. You also are provided with the noise measurement and how much energy the unit would use in a year according to the standards set.
With Brexit it looks like energy labelling might be delayed or possibly adapted for the popular cordless vacuum cleaner and the water based vacuums.