Its unlikely to be a deciding factor. A reviewer position would signal that you have a significant research contribution before your PhD, one that has caught the attention of reputed researchers in your field. This would be rare for the top-journals in many fields, so it will attract attention, generally positive.
It could back-fire if, in an interview, you are unable to answer simple/current questions related to the field you reviewed in. This could suggest that you were inappropriately assigned the review, and further that you are opportunistically using the review role to improve your application.