Two years should bring you near-fully matured specimens. All roses, regardless of size or type, take at least two years to develop to their full size.

I put in own-root ones last spring, all in pots, and most of them did
not do much. This year they are really taking off and I have potted them all up into much bigger containers. I expect they will
have to go into the ground by fall. I'm in San Diego, so I would
expect yours will really start to make a statement next spring in
LA.

I think your comment that they are in 'little' pots is the key.
I would suggest moving them to larger pots to prevent them from becoming root bound.
A plant won't put out much top growth if it doesn't have the root system to support it.
Don't move them too a very large pot suddenly as this will come with several other problems of being over watered.
Usually you move a potted plant up 1"-2" in size. Moving it to a much larger pot will surround the plant with very wet soil that will reduce the amount of oxygen around the roots.
In your area, your minis should flourish amazingly. Also consider using plastic pots rather than clay pots as these dry out too quickly outside, and you need to keep the roots moist. Allowing a mini to dry out completely will kill it quicker than most diseases.
Meg