Yes, you should always sanitize fresh. Most of the sanitizers we use are No rinse/wet contact sanitizers.
They are literally double edged swords. They kill two ways. They kill everything on the object prior to sanitizing, and then as long as they are still wet they form a sanitizer barrier that kills everything that comes into contact with object.
If you let the sanitizer dry any micro organism that comes in contact with the sanitized object, rather than being killed by it, makes the object no longer sanitzed.
If you let it dry you are reducing it's efficacy by 50%
I think you should always sanitize fresh. And on bottling day it doesn't take more than 10 minutes to sanitize them with my vinator. If you look at the system for bottling I share in the bottling sticky,
the whole process takes no more than an hour.