Yes, you can use
both. However, using
both makes the first clause plural. The clause would need to end with
multivariate models,. If you wanted it to remain singular, choosing either but not both, then you would use
either instead of
both. Since the second clause is definitely singular,
either would be a better choice.
I hope you don't mind me going beyond your question. The sentence is a little awkward, repeating the noun 'model' in close proximity. It might sound slightly better as:
For either bivariate or multivarite, the new model ..., or even
Whether bivariate or multivarite, the new model ...