两种说法都对,但是有区别.
第一句的married在这里可以看成是形容词,和happy一样,强调的是状态,“我们是夫妻”.
类似的语法例子有：
My homework is finished.
I have finished my homework.
这两句的意思差不多,但强调的不一样.
第二句强调的是动作,我们结婚了,这句可以加时间状语,比如We got married two years ago.
但 We were married two years ago. 这句话的意思就不一样了,这句话的意思是,两年前我们还是夫妻（已婚状态）,而现在已经不是夫妻了.