You have heard, "perennials sleep the first year, creep the second year and leap the third year," right? ;)

FataMorgana

Punk, horticulturally speaking, your rosemary is a woody shrub. As such, what you've described is pretty much normal for a late summer/fall planting. In your mild climate, the roots will continue to develop over the winter and as soon as the days begin to get longer in the spring, you'll see new growth. And you are correct, rosemary is considered a slow grower...slow but steady once established.

Do not be tempted to fertilize your plants "in order to get them to grow faster". The last thing you want to do is to force a bunch of new growth before the plant is ready to support it...and before the onset of some chilly temperatures.

Fatamorgana has put it very well indeed. Rosemary is very slow to start with, and yours is very much still an infant. Give it another couple of years, and then it'll take off.

Rule of thumb put another way: the longer a plant's life-expectancy, the slower it is to grow. A huge forest tree can take hundreds of years to reach maturity. Some annuals can live their entire life-cycle in a matter of a couple of weeks.

Rosemary can live more than 30 years.

And Rhizo is correct, too. Think of plants as being not unlike people in many ways. You can feed up your children to the eyeballs, but they won't grow up any faster - you'll just be making them unhealthy by over-feeding! Rosemary does better with a lean diet.

It will enjoy the winter season and then it should take off. One thing I did found out the hard way was I thought I could bury the branches that were on the ground. They all died, cuttings work well in the fall through the winter season better or early spring before it turns hot. In 3 years my rosemary was over 3 by 3 feet. I try to provide starts to my friends and neighbors as they do well in this area.

I see where someone says to use the tender not the woody portions.

One of the plants is the original plant I bought Spring 2014 to replace my big one which froze. I dug it up late in the year and put it in a large pot.
The other is much smaller, from a cutting I took off of that in the fall. Yes it probably was woody. I can try a green shoot. But I have in the past just stabbed long cuttings into the dirt and lots of those lived and did fine.

But why does the original plant have no oomph? I re-planted it where It grew OK last year.

I am in 6b east coast US. Like you, I have been over wintering rosemaries. I find a cold garage with some small degree of light is sufficient. But I will never plant rosemary in the ground again, as disturbing roots seems to have an ill effect. Also, I will not overwinter rosemary in heated area again... this seems to force the plant to grow and weaken in the process.

My biggest rosemary is growing in a wide 25 liter pot now in its 3rd year and is bushing out nicely. I will probaby upgrade to a pot twice the size if I can keep it healthy for another two years.

I started mine from seed and oh boy - that's the slowest growing plant I ever saw other than Butterfly weed. Which i wouldn't recommend unless you have a lot of patience. What is the deal?