Once in the ground, geosynthetics (geotextiles & geogrids) will last pretty much forever, as long as the soil is not biologically or chemically contaminated. As previously stated, all geosynthetics are suspect to UV degradation. Industry standards recommend geosynthetics be covered with soil within 14 days of deployment.
That being said there are higher UV packages that can be added to geosyntehtics to increase the UV stability. There are also materials now being used in wrapped face retaining walls with vegetated facing that will last for the life of the structure, typically 100 year design life.
Check with each manufaturer as not all geosyntehics are created equally.