FRANKFURT (Reuters) – Euro zone wages are climbing after a lost decade but some pay rises may prove fleeting as employers across the bloc opt to give one-off bonuses rather than permanent increases against an uncertain outlook for growth and inflation. The preference for temporary increases may be frustrating for workers struggling with a cost-of-living crisis but it will be welcomed by European Central Bank policymakers fearing a self-reinforcing spiral between wages and inflation. At 8%, inflation is so high that families are quickly losing their purchasing power, so it is only a matter of t…