You may want to treat the Poinsettia separately fron the Chrysanthemum or try leavig them in the same pot. I described how to get the Poinsettia to bloom again in a thread called Poinsettas in houseplants. As for the Chrysanthemum....

After the Chrysanthemum flowers fade, prune the plant back to half its isze, place it on a windowsill that receives some direct sunlight, water thoroughly whenever the top soil layer feels dry, fertilize every month with a water-soluble chemical fertilizer high in phosphorous and maintain the temperature at 65F.

After the last frost, likely in mid spring, the Chrysanthemum can be taken outside either in it's pot or planted in the ground. Mums are perennial and their natural flowering time is autumn. Mums should be planted in a sunny, well-drained spot where the soil has been enriched with organic matter.

Early each summer, prune the mums to half their size. This will encourage a bushier plant and prevent it from blooming too early.

The mums can be repotted and brought back into the house before the first frost. The daily dark period must be 12-15 hours long. This will require you to place your plant in total darkness for that period each day until flower buds are well formed and color is showing in the buds. This can take anywhere from 7 - 10 weeks.