Based on my prior knowledge, the education level could potentially be a relevant feature for determining whether a client subscribes to a term deposit. Here is my analysis:

1. Tertiary Education Level: Clients with a tertiary education level may have a higher chance of subscribing to a term deposit due to their potentially higher income and financial literacy.
2. Secondary Education Level: Clients with a secondary education level may have a moderate chance of subscribing to a term deposit, as they may have some financial knowledge but not as much as those with a tertiary education.
3. Unknown Education Level: The unknown category for education level may not provide much insight into whether a client subscribes to a term deposit, as the lack of information makes it difficult to make predictions.
4. Primary Education Level: Clients with a primary education level may have a lower chance of subscribing to a term deposit due to potentially lower income and financial literacy compared to those with higher education levels.

Based on this analysis, here is the dictionary:

```json
{
    "no": ["unknown", "primary"], 
    "yes": ["tertiary", "secondary"]
}
```

Please note that I have excluded the "unknown" category from the "yes" list as it is difficult to predict. Additionally, the "no" list includes only the values that are relevant for the "no" target class, and the "yes" list includes only the values that are relevant for the "yes" target class.