Getting our doodle to "go" where we want to

[Gabby]

Our goldendoodle is 4 months old and just a love bug! As with any puppy, training has been essential and overall he has done very well with most everything except going to the bathroom where we want him to. For months my husband and I have taken him over to the side yard to potty. Used the words "go potty" and highly praised him when he goes. However, if we are not present or if we do not physically walk him over to the sideyard he will just go in the nearest grassy area. I'm a little frustrated because I was hoping to bell train him and have him run to the side yard, do his business and come back in the house. Am I expecting too much? Should I just be happy that he's going outside? The reason we don't want him pooping just anywhere is because we have a fairly large yard and I would prefer not to spend hours hunting down his "surprises". Also, we have small children that might accidentally step in it. Any tips from anyone?
I also have a new update to add. As of the last week, we noticed that Duke would pee in the sideyard circle, sniff but then hold it until we walked over by the playground area and when I wasn't looking let it out. I am pulling my hair out! So last night, he started to do the same thing and my husband says to him " if you go potty here I'll give you a treat". Within seconds, he circled and let it go. We were astonished!!!
Are treats for going in the right area the way to go? Would love to hear your tips. Also, if any of you have bell trained, I would love to hear about it.

[Becka]

It's a good thing that she figured out where her spot was without the snow--you would have had to get a sno-cone machine to get her to pee!

[Jarka, Monty & Auggie]

Both of my boys learned to ring the bells when they need (or want) to go outside. Monty ONLY goes in one designated area where we originally took him to go pee and poo. He NEVER did his business anywhere else in the backyard. We did the very same with Auggie, took him out on a leash to the side of the house where Monty goes. But if he is off leash, he goes just wherever. The grass is gone. Auggie also picked his pooping spot on the other side of the house, not where Monty goes. Perhaps with two dogs, they don't want to do their business in the same area? Who knows.