Yes, you can use the
after 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 ...