I cannot suggest a time frame, but if there is a male in with females there will likely be spawning unless the male has rejected all of the females, which doesn't sound likely from what you've posted. You will need floating plants for the bubblenest, and I would make sure there are lots of them 9entire surface won't hurt) along with lower plants and/or branches to provide refuge. If spawning does occur, the females (including the one the male spawns with) should be removed when the spawning is finished or the male may kill her/them. Here is more from Seriously Fish:
The breeding
tank should contain water of no more than 6-8″ in depth with lots of floating plants. Filtration should be gentle and air-powered filters are ideal. It is recommended to provide 2 or 3 females for the male as he can be quite hard on unwilling females. Condition the fish with live food. When a female becomes plump with eggs the male will construct a large bubblenest amongst the floating plants. He also utilises small pieces of plant within the nest. He will then begin to display to the female. As the female approaches the nest the fish can be seen touching each other with their modified
ventral fins.
Spawning occurs under the nest in the typical anabantoid embrace. The eggs float upwards and the male shepherds them into the nest. Several more spawnings occur and between 500-1200 eggs may be produced. When there are no more eggs the female is chased away. It is best to remove the female(s) at this point or she may be seriously harmed. The male then tends to the nest until the eggs hatch, usually in around 20-30 hours. The
fry become free swimming in another 4-5 days, at which point the male should also be removed. They should be fed
infusoria or liquid
fry food for the first week, after which they are large enough to accept
brine shrimp nauplii,
microworm and powdered flake. The
fry must be watched carefully and separated as different growth rates become apparent or much cannibalism will occur.
Gold Gourami is one variety (developed by humans) of several that are all the same species,
Trichopodus trichopterus; more here:
http://www.seriouslyfish.com/species/trichopodus-trichopterus/