Are you ready to commit to keeping chickens again? You've done it before so you know how they tie you down with respect to needing to be cared for on a regular basis. They add a level of complexity to vacations or just going out for the afternoon and night, let alone feeding, watering, and collecting eggs daily. And the extra expense. If you are not willing to commit then you are just interested in catching them.
If you are willing to commit, determine the extent of that commitment. How many chicken will you ultimately have and plan for that. In the meantime catch those two and fix up something temporary for them. It doesn't have to be fancy.
How do you catch them? As Diva said, a traditional way is to find where they are sleeping and catch them in the dark. That's often easier to say than done. Bantams are likely to be sleeping pretty high in a tree, plus they are trying to hide. Even if you can find them it may not be safe for you to try to climb up to get them, especially in the dark. But maybe you will be lucky and can get to them with a ladder.
Then a version of RWise/Aart's idea. It doesn't have to be a coop though you can wait on that if you wish. You can build a covered wire pen with a door you can close with a long string, probably where you are feeding them that cracked corn. Leave a trail of corn into it with a pile at the far end. You can do that with the door open for a couple of days until they get used to going in or if you are really patient you might try getting them the first day. But make sure it is a long string so you don't flush them and make sure you can keep that door closed once you spring the trap.
There are various types of live traps you can try. Most of those will only get one at a time, but if you get one and pen it somewhere out there, the other will be attracted to that area and may be easier to catch.
