HMMMM, in my area Chipotle, nor Sonic, not Chilis (don’t know about Target or Panera) has put up any “no guns allowed” signs. In Texas, a business can completely ban legal firearms only by posting the state required bi-lingual 30.06 sign and none of these companies have done so. According to the law, if alcohol is sold or served in the business, a sign stating that only licensed concealed carry handguns are allowed is required. Expressing a desire that no guns be brought into a business is completely different than actually banning legal guns being brought into that business here in Texas.
As I understand from my CC instructor, one is in violation of the law if one carries into an establishment with a legally posted 30.06 sign or one of the several always prohibited areas such as a school or a building where over __% of the sales is derived from alcohol(like a bar, but not a TGIF).
Also, a CC holder is obligated to leave the premises if any proprietor discerns a weapon on an individual that would otherwise be concealed.
That’s my understanding, as the instructor was very specific.