I have never eaten Subway but I was thinking I may try it at some point. Is the Subway wheat bread SBD friendly?

No, sorry. I think it's listed on the website but their wheat bread is not made with all whole grain flour. They do have salads, which might be good - I don't know, cause I don't eat there. If you can find a sub roll that meets the guidelines for bread posted in the FAQs, you could make them at home. I don't think Subway does anything special, just slaps, some meat, cheese, veggies, and condiments on a roll.

I do get their salad but it's like $5, I just get oil and vinegar as a dressing. They use to do low carb wraps, don't know what happened to those.

Well thats out. I wonder why they would not use Whole grain flour? Whole wheat bread is sooo good and I am sure it would bring in more customers.

sadly those that worry about such things as whole grains tend not to eat out much...

We eat out. Not as much as we used to, but we still eat out. I tend to just not eat any breads, pastas, rice or potatoes. I will eat a baked sweet potato if that is a choice. I find plenty of menu items that are safe. We tend to go to the same restaurants over and over so we know the menus and what is SBD friendly.
We don't eat at subway, we do eat at potbelly's which is kind of like subway. We get their salads and use the ff or low cal (i can't remember which) viniagrette. DH also will take the top off of a sandwich and eat just one layer of bread. He doesn't have as much to lose and is not as strict with his food choices as I am. I wouldn't eat at places like subway/potbelly's too much as their meats are loaded with salt. We have their salads 1-2 times per month.