No you should not be concerned one bit. Until you get into the extreme recoiling cartridges, like 375 mags and larger, there is no problem at all with using aluminum bases and rings.

Your .270 will hold up just fine with the Talley set you purchased.

Look at Weaver rings and bases. Nearly all of them are aluminum. They have been used on probably every gun cartridge combo made at one time or another. Some even consider them to be one of the strongest mounts made.