Thank you for your question. First off I wouldn't repot while it is in full bloom.

Oncidium (dancing lady orchid) is a very diverse genus of orchids that originate in dramatically different habitats of the Americas. Over 450 species include terrestrial, epiphytic and lithophytic orchids. The most beneficial routine of care varies, and one set of instructions does not suit all Oncidium. Save the name tag on your Oncidium orchid when you make your purchase so that you can confirm the best conditions for your specific plant.

The Oncidium intergeneric hybrids can be lightly to strongly fragrant, are relatively easy to grow and widely available. Their care routine is summarized our Guide to Oncidium Intergeneric Hybrid Care. If you know the name of the Oncidium you purchased, please contact us at PlantInfo@NYBG.org for more specific instructions.

Regarding the pseudo bulbs pleating, here's what I found:

Oncidiums and their relatives like a freely draining potting mixture. Check the condition of the lead pseudo bulb or fleshy leaves for signs of hydro-insufficiencies. The lead bulb and the two behind it should be plump, and mule-ear and equitant leaves should look reasonably plump and unwrinkled. Pleated foliage could be the result of low humidity (not being in a greenhouse) or a buildup of sticky exudates that some plants secrete from developing leaves. I’m voting for low humidity, since home interiors are pretty dry, really dry, unless you have a humidifier going. In addition, older pseudo bulbs will pleat somewhat. If it is the sticky problem, you can give it a lukewarm ten-minute shower only every few weeks during its vegetative growth spurts.Orchids which have too little light will look lanky and not bloom properly,

More here from American Orchid Society http://www.aos.org/orchids/culture-sheets/oncidium.aspx

Courtesy of NYBG Plant Information Service