@Raggnorr IV : The short answer to your question is yes: both standard and Premium Expansions (when placed) will increase both your Tournament and Spire Squad Sizes and Negotiation costs, with Premium Expansions having, I believe (but not sure), ~60% of the effect of standard Expansions.
We are often told that it is the policy of InnoGames not to release any detailed information on the game mechanics, although some general information regarding how one's City progression affects Tournament and Spire Combat and Negotiating difficulty, without detailed underlying figures or calculations, can be found in the Official Announcement of the changes to the Tournaments, here:
Because many players do wish to know detailed figures,
@MinMax Gamer has created online calculators (based on crowdsourced in-game data) which will give you an accurate answer to
exactly how much effect a placed Expansion (as well as the other relevant factors, which are highest Relic Boost, Research, and AW levels) will have upon your Tournament and Spire demands. These calculators, with explanatory information, can be found here: