Wow - this plant can be expected to have well in excess of 100 blooms on a tall branching stem. They will be predominantly brown petals and sepals with a wine red lip and measure about 3-4cm round.
Oncostele is part of the Oncidiinae family, which traditionally includes Odontoglossums, Oncidiums and other intergeneric hybrids. There are now a 100 or so species which originate from the mountainous regions of Central America to the northern parts of South America.
Oncidiums, Odontoglossums and their hybrids are another orchid which will grow well alongside your Cymbidiums. They thrive outdoors in shady to dappled light - ensuring they get plenty of light will ensure that flowering will not be inhibited. Many do well on slabs, where they benefit from the rapid alteration of wet to dry if they are watered daily and dry fast. Additionally, most do very well in an intermediate greenhouse; with a minimum night temperature of 12°C as average.