In this context, a gamme is a range of products while a série is a sequence of products.
They might be interchangeable like in your example but beware that it is not always the case.
A gamme often encompass the whole range of the products a manufacturer is building while a serie is a subset of it.
For example, the gamme of cars sold by BMW is a suite of séries: Série 1, Série 2, Série 3 and so on.
There are also some idioms like:
Fin de série: The last models of a kind being produced.
Série limitée: A short number of models produced with specific features (either optional ones included for the same price, or unique features or quality). Compare to Gamme limitée that means a narrow range of products.
There is also de série that means either being included in the standard model (opposed to en option), or being available as a standard model (opposed to prototype or sur mesure).