Is this prayer recognized in the Nyingma Tradition? And if so is this the way it is spelled/pronounced?
SANG GYE CHO DANG TSOG KYI CHOG NAM LA
JANG CHUB BAR DU DAG NI KYAB SU CHI
DAG GI JIN SOK GYI PAY SO NAM KYI
DRO LA PAN CHIR SANG GYE DRUB PAR SHOG
I take refuge until I am enlightened in the Buddhas, the Dharma, and the Sangha.
By the positive potential I create by practicing generosity
and the other far-reaching attitudes,
may I attain Buddhahood in order to benefit all sentient beings.
Surely it's 'recognised.' You can use it if you want.
There are also different refuge and bodhicitta verses in Nyingma tradition, but it doesn't matter if you want to use this Kadampa one.
There can be difference at this sentence: 'DAG GI JIN SOK GYI PAY SO NAM KYI'
The meaning is .... my merits of generousity and so on....
sometimes it would be changed to .... my merits of this practice and so on....
but this difference is not about Nyingma-Sarma, and I don't think it's a big deal.
The main point is to really generate the mind of refuge and intention. So pronounciation is probably not that important either. However, Nyingma school is popular in Kham area, maybe your Nyingma master would have a Kham accent and sound a bit different. Again it's not a big deal. We are foreigners, no matter what accent we learn, we all sound not-Tibetan. and even we can speak perfect Tibetan, so what? Buddha Sakyamuni was from India, but don't need to speak perfect ancient Indian to pray to him.