I have many potted peony plants that I have planted here. Gardenia came from Home Depot, and it's has bloomed every years since I planted it.
Wladislawa, Sorbet and Immaculee came from Lowes, and they have also increased in size and bloomed every year. Rosabel, that was planted 2 years ago, has not yet bloomed, but puts up stem.
My favorite local nursery for potted peonies is Pikes. I have Itohs Yumi, Misaka, and Keiko that came in 3 gallon pots (talk about instant gratification with the blooms) and they have bloomed and increased in size every year. Takara has not yet bloomed.
Also from Pikes were Blaze, Bowl of Cream, Buckeye Belle, Do Tell, Festiva Maxima, Lady Orchid, Sea Shell, Kansas, Karl Rosenfeld, Inspecteur Lavergne, Nancy Nora, Pink Parfait, Jan Van Leeuwen, and Scarlet Ohara. Most of these plants have bloomed since they were planted.
I also like getting tubers from the various mail order vendors, and a few of them will bloom the first year after they have been planted. Tubers bought locally tend to be puny, so I pot them up, baby them, and may keep them in pots for 6 months to a year before planting them in the ground.
I don't plant the potted plants in the ground until in the fall, when the ground starts to cool down.