Thanks for writing. Some vines mature a little faster than others --- just like people. You may need to be patient and give it another week or two.
In the meantime, be sure it's in full sun (shade can keep it from blooming) and take care not to fertilize it too much; overly rich soil will cause it to put on all leafy growth at the expense of blooms.
---Justin, Senior Garden Editor, BHG.com