Playfair Cipher + Vigenere Cipher?
The short answer is yes. It would be considerably more secure.

But nowadays, classical encryption methods like Playfair and Vigenère are so easily broken by computer analysis that they offer next to no security whatsoever. Aiming for something "considerably more secure" than either of these is really setting the bar very low.

Specifically, although the combination of Playfair and Vigenère does reduce the frequency of repeated sequences, it doesn't get rid of them. So you still haven't eliminated the primary weakness of vanilla Vigenère.

For example, if your Vigenère key has length $n$, just one repetition of a word at an interval of $2kn$ places provides enough information to get started on an attack. You obviously don't know what the value of $k$ is, but there's nothing to stop you testing for key lengths corresponding to every divisor of $2kn$.

Even if your plaintext contains no repeated words whatsoever, you're still vulnerable to the same attack if the same word appears in more than one message. (Unless, of course, you use a different set of keys every time, in which case you may as well use a one-time pad.)

This system would also fail according to Kerckhoffs's principle:


  A cryptosystem should be secure even if everything about the system, except the key, is public knowledge.